Provided by: cmake-data_3.28.3-1build7_all 
NAME
cmake-commands - CMake Language Command Reference
SCRIPTING COMMANDS
These commands are always available.
block
New 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")
block(PROPAGATE var1 var2)
set(var1 "VALUE1")
unset(var2)
endblock()
# Now var1 holds VALUE1, and var2 is unset
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
New in version 3.10.
One if processor is 64Bit
HAS_FPU
New in version 3.10.
One if processor has floating point unit
HAS_MMX
New in version 3.10.
One if processor supports MMX instructions
HAS_MMX_PLUS
New in version 3.10.
One if processor supports Ext. MMX instructions
HAS_SSE
New in version 3.10.
One if processor supports SSE instructions
HAS_SSE2
New in version 3.10.
One if processor supports SSE2 instructions
HAS_SSE_FP
New in version 3.10.
One if processor supports SSE FP instructions
HAS_SSE_MMX
New in version 3.10.
One if processor supports SSE MMX instructions
HAS_AMD_3DNOW
New in version 3.10.
One if processor supports 3DNow instructions
HAS_AMD_3DNOW_PLUS
New in version 3.10.
One if processor supports 3DNow+ instructions
HAS_IA64
New in version 3.10.
One if IA64 processor emulating x86
HAS_SERIAL_NUMBER
New in version 3.10.
One if processor has serial number
PROCESSOR_SERIAL_NUMBER
New in version 3.10.
Processor serial number
PROCESSOR_NAME
New in version 3.10.
Human readable processor name
PROCESSOR_DESCRIPTION
New in version 3.10.
Human readable full processor description
OS_NAME
New in version 3.10.
See CMAKE_HOST_SYSTEM_NAME
OS_RELEASE
New in version 3.10.
The OS sub-type e.g. on Windows Professional
OS_VERSION
New in version 3.10.
The OS build ID
OS_PLATFORM
New in version 3.10.
See CMAKE_HOST_SYSTEM_PROCESSOR
MSYSTEM_PREFIX
New 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
New in version 3.22.
Read /etc/os-release file and define the given <variable> into a list of read variables
DISTRIB_<name>
New 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
New 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
New 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>)
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
New 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
New 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.
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_MAKEAVAILABE_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
New 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.
cmake_minimum_required
Require a minimum version of cmake.
cmake_minimum_required(VERSION <min>[...<policy_max>] [FATAL_ERROR])
New in version 3.12: The optional <policy_max> version.
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 affects policy settings as described in Policy Settings. 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 Settings
The cmake_minimum_required(VERSION) command implicitly invokes the cmake_policy(VERSION) command to
specify that the current project code is written for the given range of CMake versions. All policies
known to the running version of CMake and introduced in the <min> (or <max>, if specified) version or
earlier will be set to use NEW behavior. All policies introduced in later versions will be unset. This
effectively requests behavior preferred as of a given CMake version and tells newer CMake versions to
warn about their new policies.
When a <min> version higher than 2.4 is specified the command implicitly invokes
cmake_policy(VERSION <min>[...<max>])
which sets CMake policies based on the range of versions specified. When a <min> version 2.4 or lower is
given the command implicitly invokes
cmake_policy(VERSION 2.4[...<max>])
which enables compatibility features for CMake 2.4 and lower.
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>)
New 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 processes arguments passed in the <args>.... This may be used in either a
macro() or a function().
New 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 macro, i.e. keywords which can be used
when calling the macro without any value following, like e.g. the OPTIONAL keyword of the install()
command.
The <one_value_keywords> argument contains all keywords for this macro which are followed by one value,
like e.g. DESTINATION keyword of the install() command.
The <multi_value_keywords> argument contains all keywords for this macro which can be followed by more
than one value, like e.g. the TARGETS or FILES keywords of the install() command.
Changed in version 3.5: All keywords shall be unique. I.e. every keyword shall only be specified once in
either <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. These variables will then hold the respective value from the
argument list or be undefined if the associated option could not be found. For the <options> keywords,
these will always be defined, to TRUE or FALSE, whether the option is in the argument list or 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 was called with
unrecognized parameters.
New 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.
Consider the following example macro, my_install(), which takes similar arguments to the real install()
command:
macro(my_install)
set(options OPTIONAL FAST)
set(oneValueArgs DESTINATION RENAME)
set(multiValueArgs TARGETS CONFIGURATIONS)
cmake_parse_arguments(MY_INSTALL "${options}" "${oneValueArgs}"
"${multiValueArgs}" ${ARGN} )
# ...
Assume my_install() has been called like this:
my_install(TARGETS foo bar DESTINATION bin OPTIONAL blub CONFIGURATIONS)
After the cmake_parse_arguments call the macro will have set or undefined the following variables:
MY_INSTALL_OPTIONAL = TRUE
MY_INSTALL_FAST = FALSE # was not used in call to my_install
MY_INSTALL_DESTINATION = "bin"
MY_INSTALL_RENAME <UNDEFINED> # was not used
MY_INSTALL_TARGETS = "foo;bar"
MY_INSTALL_CONFIGURATIONS <UNDEFINED> # was not used
MY_INSTALL_UNPARSED_ARGUMENTS = "blub" # nothing expected after "OPTIONAL"
MY_INSTALL_KEYWORDS_MISSING_VALUES = "CONFIGURATIONS"
# No value for "CONFIGURATIONS" given
You can then continue and process these variables.
Keywords terminate lists of values, e.g. if directly after a one_value_keyword another recognized keyword
follows, this is interpreted as the beginning of the new option. E.g. my_install(TARGETS foo
DESTINATION OPTIONAL) would result in MY_INSTALL_DESTINATION set to "OPTIONAL", but as OPTIONAL is a
keyword itself MY_INSTALL_DESTINATION will be empty (but added to MY_INSTALL_KEYWORDS_MISSING_VALUES) and
MY_INSTALL_OPTIONAL will therefore be set to TRUE.
See Also
• function()
• macro()
cmake_path
New 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 \"${path}\"")
# filename is now already empty, the following removes nothing
cmake_path(REMOVE_FILENAME path)
message("Second path is \"${result}\"")
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_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>])
New 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. All
policies known to the running version of CMake and introduced in the <min> (or <max>, if specified)
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 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.
New 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 and substitutes variable values referenced as @VAR@, ${VAR},
$CACHE{VAR} or $ENV{VAR} in the input file content. Each variable reference will 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.
New 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
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.
The arguments 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
New 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
New 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>...
New 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 ${VAR} syntax.
NEWLINE_STYLE <style>
Specify the newline style for the output file. Specify UNIX or LF for \n newlines, or specify
DOS, WIN32, or CRLF for \r\n newlines. This option may not be used with COPYONLY.
Example
Consider a source tree containing a foo.h.in file:
#cmakedefine FOO_ENABLE
#cmakedefine FOO_STRING "@FOO_STRING@"
An adjacent CMakeLists.txt may use configure_file to configure the header:
option(FOO_ENABLE "Enable Foo" ON)
if(FOO_ENABLE)
set(FOO_STRING "foo")
endif()
configure_file(foo.h.in foo.h @ONLY)
This creates a foo.h in the build directory corresponding to this source directory. If the FOO_ENABLE
option is on, the configured file will contain:
#define FOO_ENABLE
#define FOO_STRING "foo"
Otherwise it will contain:
/* #undef FOO_ENABLE */
/* #undef FOO_STRING */
One may then use the target_include_directories() command to specify the output directory as an include
directory:
target_include_directories(<target> [SYSTEM] <INTERFACE|PUBLIC|PRIVATE> "${CMAKE_CURRENT_BINARY_DIR}")
so that sources may include the header as #include <foo.h>.
See Also
• file(GENERATE)
continue
New 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.
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
New 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>])
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.
• On Windows platforms, the command line is encoded as a string such that child processes using
CommandLineToArgvW will decode the original arguments.
No intermediate shell is used, so shell operators such as > are treated as normal arguments. (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>
New 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.
New 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
New 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>
New 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>
New 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 is the default.
AUTO Use the current active console's codepage or if that isn't available then use ANSI.
ANSI Use the ANSI codepage.
OEM Use the original equipment manufacturer (OEM) code page.
UTF8 or UTF-8
Use the UTF-8 codepage.
New in version 3.11: Accept UTF-8 spelling for consistency with the UTF-8 RFC naming
convention.
COMMAND_ERROR_IS_FATAL <ANY|LAST>
New 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.
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> [...])
file(GET_RUNTIME_DEPENDENCIES [...])
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 [<dir>...])
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> [...])
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).
ENCODING <encoding-type>
New 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.
New 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.
file(GET_RUNTIME_DEPENDENCIES [...])
New 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>
New 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>
New 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.
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 if set,
else by system introspection.
New in version 3.18: Use CMAKE_OBJDUMP if set.
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>...])
New 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.
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>
New 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
New in version 3.20.
The generated file permissions default to the standard 644 value (-rw-r--r--).
USE_SOURCE_PERMISSIONS
New 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>...
New in version 3.20.
Use the specified permissions for the generated file.
NEWLINE_STYLE <style>
New 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] ])
New 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.
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.
New in version 3.3: By default GLOB lists directories. Directories are omitted in the result if
LIST_DIRECTORIES is set to false.
New 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.
New 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>...])
Create the given directories and their parents as needed.
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>
New 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
New 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])
New 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
New 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.
New 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>)
New 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>)
New 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])
New 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>...])
New 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>...])
New 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])
New 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
New 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>.
New 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>
New in version 3.7.
Set username and password for operation.
HTTPHEADER <HTTP-header>
New 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>
New 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>
New 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_VERIFY <ON|OFF>
Specify whether to verify the server certificate for https:// URLs. The default is to
not verify. If this option is not specified, the value of the CMAKE_TLS_VERIFY variable
will be used instead.
New 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.
New in version 3.18: Added support to file(UPLOAD).
For https:// URLs CMake must be built with OpenSSL support. TLS/SSL certificates are not checked
by default. Set TLS_VERIFY to ON to check certificates.
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>
New 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>
New 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>])
New 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>] [VERBOSE])
New 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.
Use the FORMAT option to 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.
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.
New 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.
New in version 3.26: The <compression-level> of the Zstd algorithm can be set between 0-19.
NOTE:
With FORMAT set to raw, only one file will be compressed with the compression type specified by
COMPRESSION.
The VERBOSE option enables verbose output for the archive operation.
To specify the modification time recorded in tarball entries, use the MTIME option.
file(ARCHIVE_EXTRACT INPUT <archive> [DESTINATION <dir>] [PATTERNS <patterns>...] [LIST_ONLY] [VERBOSE]
[TOUCH])
New in version 3.18.
Extracts or lists the content of the specified <archive>.
The directory where the content of the archive will be extracted to can be specified using the
DESTINATION option. If the directory does not exist, it will be created. If DESTINATION is not
given, the current binary directory will be used.
If required, you may select which files and directories to list or extract from the archive using
the specified <patterns>. Wildcards are supported. If the PATTERNS option is not given, the
entire archive will be listed or extracted.
LIST_ONLY will list the files in the archive rather than extract them.
New in version 3.24: The TOUCH option gives extracted files a current local timestamp instead of
extracting file timestamps from the archive.
With VERBOSE, the command will produce verbose output.
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
New 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
New 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
New 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
New 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.
New 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.
New 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.
New 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.
New 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
New 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
New 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
New 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
New 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.
New 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.
New 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.
New 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.
New 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 a library file name and then
considered with platform-specific prefixes (e.g. lib) and suffixes (e.g. .so). 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.
New 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.
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).
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
New 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.
Where possible, user code should generally look for packages using the basic signature, since that allows
the package to be found with any mode. Project maintainers wishing to provide a config package should
understand the bigger picture, as explained in Full Signature and all subsequent sections on this page.
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. Formally, it is 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.
New 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.
New 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.
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]). Version support is currently provided only on a package-by-package basis (see the Version
Selection section below). 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.
See the cmake_policy() command documentation for discussion of the NO_POLICY_SCOPE option.
New 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.
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 CMake 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.
New 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>/ │ W │
├────────────────────────────────────────────────────────────────┼────────────┤
│<prefix>/(cmake|CMake)/ │ W │
├────────────────────────────────────────────────────────────────┼────────────┤
│<prefix>/<name>*/ │ W │
├────────────────────────────────────────────────────────────────┼────────────┤
│<prefix>/<name>*/(cmake|CMake)/ │ W │
├────────────────────────────────────────────────────────────────┼────────────┤
│<prefix>/<name>*/(cmake|CMake)/<name>*/ │ W │
│[1] │ │
├────────────────────────────────────────────────────────────────┼────────────┤
│<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] New in version 3.25.
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/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/ │ A │
├──────────────────────────────────────────────────────┼────────────┤
│<prefix>/<name>.app/Contents/Resources/CMake/ │ A │
└──────────────────────────────────────────────────────┴────────────┘
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.
New 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.
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.
New 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.
New 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.
New 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.
New in version 3.16: Added the CMAKE_FIND_USE_<CATEGORY> variables to globally disable various search
locations.
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. 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. When multiple package configuration files
are available whose version files claim compatibility with the version requested it is unspecified which
one is chosen: unless the variable CMAKE_FIND_PACKAGE_SORT_ORDER is set no attempt is made to choose a
highest or closest version number.
To control the order in which find_package checks for compatibility use the two variables
CMAKE_FIND_PACKAGE_SORT_ORDER and CMAKE_FIND_PACKAGE_SORT_DIRECTION. For instance in order to select the
highest version one can set
SET(CMAKE_FIND_PACKAGE_SORT_ORDER NATURAL)
SET(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)
before calling find_package.
Package File Interface Variables
When loading a find module or 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.
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
New 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
New 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
New 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
New 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.
New 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.
New 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.
New 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.
New 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
New 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
New 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
New 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
New 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.
New 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.
New 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.
New 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.
New 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.
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>)
New 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.
New 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.
New 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)
New 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])
New 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.
New 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.
New 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.
New 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
New 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.
New 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 an empty value is returned, 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 EXISTS, COMMAND, 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, 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
• 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>)
New 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}).
New in version 3.14: Added support for CACHE{<name>} variables.
if(<variable|string> IN_LIST <variable>)
New 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.
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.
New 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>)
New 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>)
New 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>)
New 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>)
New 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>)
New 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>)
New 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>)
New in version 3.24.
Compares the two paths component-by-component. 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.
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 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
New 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>)
New 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>)
New 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>)
New 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>...])
New 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>...])
New 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> ...])
New 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>])
New 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.
New in version 3.13: Added the COMPARE, CASE, and ORDER options.
New 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.
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.
New 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 function 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.
New in version 3.13: Hexadecimal numbers are recognized when prefixed with 0x, as in C code.
New 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.
New 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.
New 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.
New 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.
New 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
New 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: ${missingComponents}")
else()
message(CHECK_PASS "all components found")
endif()
Output from the above would appear something like the following:
-- Finding my things
-- Finding partA
-- Finding partA - found
-- Finding partB
-- Finding partB - not found
-- Finding my things - missing components: B
Configure Log
New in version 3.26.
message(CONFIGURE_LOG <text>...)
Record a configure-log message event with the specified <text>. By convention, if the text contains more
than one line, the first line should be a summary of the event.
This mode is intended to record the details of a system inspection check or other one-time operation
guarded by a cache entry, but that is not performed using try_compile() or try_run(), which automatically
log their details. Projects should avoid calling it every time CMake runs. For example:
if (NOT DEFINED MY_CHECK_RESULT)
# Print check summary in configure output.
message(CHECK_START "My Check")
# ... perform system inspection, e.g., with execute_process ...
# Cache the result so we do not run the check again.
set(MY_CHECK_RESULT "${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
New 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_version_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
New in version 3.9.
Proceeds as in WINDOWS_COMMAND mode if the host system is Windows. Otherwise proceeds as in
UNIX_COMMAND mode.
PROGRAM
New 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.
New 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).
New 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.
New 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
New 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.
New 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
[^ ] Matches any character(s) not inside the brackets
- 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.
New 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>...])
New in version 3.4.
Append all the <input> arguments to the string.
string(PREPEND <string_variable> [<input>...])
New 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>...])
New 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>)
New 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>)
New 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>.
New 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.
New 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>)
New 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:
%% New 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 New in version 3.7.
Abbreviated month name (e.g. Oct).
%B New in version 3.10.
Full month name (e.g. October).
%M The minute of the current hour (00-59).
%s New 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 New in version 3.23.
The microsecond of the current second (000000-999999).
%U The week number of the current year (00-53).
%V New 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 New in version 3.7.
Abbreviated weekday name (e.g. Fri).
%A New 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 New in version 3.26.
The offset of the time zone from UTC, in hours and minutes, with format +hhmm or -hhmm.
%Z New 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.
New 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])
New 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
New 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.
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
New 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).
New 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.
New 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]
[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
New 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.
New 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. 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).
• New 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.
New 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.
New 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.
New in version 3.1: Arguments to DEPENDS may use generator expressions.
COMMAND_EXPAND_LISTS
New 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.
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
New 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
New 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.
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.
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.
New 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.
USES_TERMINAL
New 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.
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.
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.
New in version 3.13: Arguments to WORKING_DIRECTORY may use generator expressions.
DEPFILE
New 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.
New in version 3.7: The Ninja generator supports DEPFILE since the keyword was first added.
New in version 3.17: Added the Ninja Multi-Config generator, which included support for the
DEPFILE keyword.
New 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.
New 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.
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.
DEPENDS_EXPLICIT_ONLY
New 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.
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 ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
VERBATIM)
add_library(myLib out.c)
adds a custom command to run someTool to generate out.c and then compile the generated source as part of
a library. The generation rule will re-run whenever in.txt changes.
New in version 3.20: One may use generator expressions to specify per-configuration outputs. For
example, the code:
add_custom_command(
OUTPUT "out-$<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.
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])
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. For backward
compatibility reasons, POST_BUILD is assumed if no such keyword is given, but projects should explicitly
provide one of the keywords to make clear the behavior they expect.
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 12 2013 (and newer) generators these command lines or custom commands will be omitted for the
specific configuration and no "empty-string-command" will be added.
This allows to add individual build events for every configuration.
New in version 3.21: Support for target-dependent generator expressions.
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 "$<TARGET_FILE:myExe>.hash"
VERBATIM)
will run someHasher to produce a .hash file next to the executable after linking.
New in version 3.20: One may use generator expressions to specify per-configuration byproducts. For
example, the code:
add_library(myPlugin MODULE myPlugin.c)
add_custom_command(
TARGET myPlugin POST_BUILD
COMMAND someHasher -i "$<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
New 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
New 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.
New 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).
• New 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.
New 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
New 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
New 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
New 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
New 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.
New in version 3.13: Arguments to WORKING_DIRECTORY may use generator expressions.
Ninja Multi-Config
New 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).
Dependencies added to an imported target or an interface library are followed transitively in its place
since the target itself does not build.
New in version 3.3: Allow adding dependencies to interface libraries.
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> [WIN32] [MACOSX_BUNDLE]
[EXCLUDE_FROM_ALL]
[source1] [source2 ...])
Adds an executable target called <name> to be built from the source files listed in the command
invocation. 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>).
New 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.
New 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.
If WIN32 is given the property WIN32_EXECUTABLE will be set on the target created. See documentation of
that target property for details.
If MACOSX_BUNDLE is given the corresponding property will be set on the created target. See
documentation of the MACOSX_BUNDLE target property for details.
If EXCLUDE_FROM_ALL is given the corresponding property will be set on the created target. See
documentation of the EXCLUDE_FROM_ALL target property for details.
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])
An IMPORTED executable target references an executable file located outside the project. No rules are
generated to build it, and the IMPORTED target property is True. The target name has scope in the
directory in which it is created and below, but the GLOBAL option extends visibility. It may be
referenced like any target built within the project. 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.
New in version 3.11: An ALIAS can target a GLOBAL Imported Target
New 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> [STATIC | SHARED | MODULE]
[EXCLUDE_FROM_ALL]
[<source>...])
Adds a library target called <name> to be built from the source files listed in the command invocation.
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).
New 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.
New in version 3.11: The source files can be omitted if they are added later using target_sources().
STATIC, SHARED, or MODULE may be given to specify the type of library to be created. STATIC libraries
are archives of object files for use when linking other targets. SHARED libraries are linked dynamically
and loaded at runtime. MODULE libraries are plugins that are not linked into other targets but may be
loaded dynamically at runtime using dlopen-like functionality. If no type is given explicitly the type
is STATIC or SHARED based on whether the current value of the variable BUILD_SHARED_LIBS is ON. 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.
New 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.
If EXCLUDE_FROM_ALL is given the corresponding property will be set on the created target. See
documentation of the EXCLUDE_FROM_ALL target property for details.
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.
Object Libraries
add_library(<name> OBJECT [<source>...])
Creates an Object Library. An object library compiles source files but does not archive or link their
object files into a library. Instead 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>.
New in version 3.12: Object libraries can be linked to with target_link_libraries().
Interface Libraries
add_library(<name> INTERFACE)
Creates an Interface Library. An INTERFACE library target does not compile sources and does not produce
a library artifact on disk. 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.
An interface library created with the above signature has no source files itself and is not included as a
target in the generated buildsystem.
New 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.
New in version 3.19: An interface library target may be created with source files:
add_library(<name> INTERFACE [<source>...] [EXCLUDE_FROM_ALL])
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.
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])
Creates an IMPORTED library target called <name>. No rules are generated to build it, and the IMPORTED
target property is True. The target name has scope in the directory in which it is created and below,
but the GLOBAL option extends visibility. It may be referenced like any target built within the project.
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_.
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.
See documentation of the IMPORTED_* and INTERFACE_* 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.
New in version 3.11: An ALIAS can target a GLOBAL Imported Target
New 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
New 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
New 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.
New 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 targets in the subdirectory will not be included in the
ALL target of the parent directory by default, and will be excluded from IDE project files. Users must
explicitly build targets in the subdirectory. This is meant for use when the subdirectory contains a
separate part of the project that is useful but not necessary, such as a set of examples. Typically the
subdirectory should contain its own project() command invocation so that a full build system will be
generated in the subdirectory (such as a Visual Studio IDE solution file). Note that inter-target
dependencies supersede this exclusion. If a target built by the parent project depends on a target in
the subdirectory, the dependee target will be included in the parent project build system to satisfy the
dependency.
New 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.
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
New 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_FALL 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.
New 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>...] [-- -i]
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. The trailing --
-i option is added for Makefile Generators if policy CMP0061 is not set to NEW.
When invoked, this cmake --build command line will launch the underlying build system tool.
New 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
New 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
)
create_test_sourcelist
Create a test driver and source list for building test programs.
create_test_sourcelist(<sourceListName> <driverName>
<tests> ...
[EXTRA_INCLUDE <include>]
[FUNCTION <function>])
A test driver is a 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. The list of
source files needed to build the test driver will be in sourceListName. driverName is the name of the
test driver program. The rest of the arguments consist of a list of test source files and can be
semicolon separated. Each test source file should have a function in it that is the same name as the
file with no extension (foo.cxx should have int foo(int, char*[]);). driverName will be able to call each
of the tests by name on the command line. If EXTRA_INCLUDE is specified, then the next argument is
included into the generated file. If FUNCTION is specified, then the next argument is taken as a function
name that is passed pointers to argc and argv. This can be used to add extra command line processing to
each test. The CMAKE_TESTDRIVER_BEFORE_TESTMAIN cmake variable can be set to have code that will be
placed directly before calling the test main function. CMAKE_TESTDRIVER_AFTER_TESTMAIN can be set to
have code that will be placed directly after the call to the test main 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.
New 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.
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.
New in version 3.8: Added CSharp and CUDA support.
New in version 3.15: Added Swift support.
New in version 3.16: Added OBJC and OBJCXX support.
New in version 3.18: Added ISPC support.
New in version 3.21: Added HIP support.
New in version 3.26: Added ASM_MARMASM support.
If enabling ASM, list it last so that CMake can check whether compilers for other languages like C work
for assembly too.
This command must be called in file scope, not in a function call. Furthermore, 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 source directory root because ctest expects to find a test file in the
build directory root.
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>)
Exporting Targets
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>
New 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>)
New 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> [NAMESPACE <namespace>] [FILE <filename>]
[CXX_MODULES_DIRECTORY <directory>])
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.
Exporting Packages
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.
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.
New 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.
New 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 $<...>. See the
cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for
more on defining buildsystem properties.
NOTE:
Prefer the target_include_directories() command to add include directories to individual targets and
optionally propagate/export them to dependents.
See Also
• target_include_directories()
include_external_msproject
Include an external Microsoft project file in a workspace.
include_external_msproject(projectname location
[TYPE projectTypeGUID]
[GUID projectGUID]
[PLATFORM platformName]
dep1 dep2 ...)
Includes an external Microsoft project in the generated workspace file. Currently does nothing on UNIX.
This will create a target named [projectname]. This can be used in the add_dependencies() command to
make things depend on the external project.
TYPE, GUID and PLATFORM are optional parameters that allow one to specify the type of project, id (GUID)
of the project and the name of the target platform. This is useful for projects requiring values other
than the default (e.g. WIX projects).
New in version 3.9: If the imported project has different configuration names than the current project,
set the MAP_IMPORTED_CONFIG_<CONFIG> target property to specify the mapping.
include_regular_expression
Set the regular expression used for dependency checking.
include_regular_expression(regex_match [regex_complain])
Sets the regular expressions used in dependency checking. Only files matching regex_match will be traced
as dependencies. Only files matching regex_complain will generate warnings if they cannot be found
(standard header paths are not searched). The defaults are:
regex_match = "^.*$" (match everything)
regex_complain = "^$" (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(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().
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. Arguments can be relative or
absolute paths.
If 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.
If an absolute path (with a leading slash or drive letter) is given it is used verbatim.
As absolute paths are not supported by cpack installer generators, it is preferable to use
relative paths throughout. 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.
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.
EXCLUDE_FROM_ALL
New in version 3.6.
Specify that the file is excluded from a full installation and only installed as part of a
component-specific installation
RENAME <name>
Specify a name for an installed file that may be different from the original file. Renaming is
allowed only when a single file is installed by the command.
OPTIONAL
Specify that it is not an error if the file to be installed does not exist.
New 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.
New 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
New 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>
New 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
New 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 recommended that they use a path that begins with the appropriate
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
New 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>.
RUNTIME_DEPENDENCY_SET <set-name>
New 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>...
New 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.
New 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.
New 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>... [...])
New 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.
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 │
└──────────────┴────────────────────────────────┴───────────────────────┘
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 recommended that they use a path that begins with the appropriate
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
)
New 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.
New 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.
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.
New 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 │
└──────────────┴────────────────────────────────┴───────────────────────┘
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 recommended that they use a path that begins with the appropriate
GNUInstallDirs variable. This allows package maintainers to control the install destination by
setting the appropriate cache variables.
New 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.
New in version 3.5: The list of dirs... given to DIRECTORY may use "generator expressions" too.
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.
New 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.
New 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])
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.
New 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
New 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.
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.
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.
install(RUNTIME_DEPENDENCY_SET <set-name> [...])
New 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>...
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.
New 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.
New 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.
New 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.
load_cache
Load in the values from another project's CMake cache.
load_cache(pathToBuildDirectory READ_WITH_PREFIX prefix entry1...)
Reads the cache and store the requested entries in variables with their name prefixed with the given
prefix. This only reads the values, and does not create entries in the local project's cache.
load_cache(pathToBuildDirectory [EXCLUDE entry1...]
[INCLUDE_INTERNALS entry1...])
Loads in the values from another cache and store them in the local project's cache as internal entries.
This is useful for a project that depends on another project built in a different tree. EXCLUDE option
can be used to provide a list of entries to be excluded. INCLUDE_INTERNALS can be used to provide a list
of internal entries to be included. Normally, no internal entries are brought in. Use of this form of
the command is strongly discouraged, but it is provided for backward compatibility.
project
Set the name of the project.
Synopsis
project(<PROJECT-NAME> [<language-name>...])
project(<PROJECT-NAME>
[VERSION <major>[.<minor>[.<patch>[.<tweak>]]]]
[DESCRIPTION <project-description-string>]
[HOMEPAGE_URL <url-string>]
[LANGUAGES <language-name>...])
Sets the name of the project, and stores it in the variable PROJECT_NAME. When called from the top-level
CMakeLists.txt also stores the project name in the variable CMAKE_PROJECT_NAME.
Also sets the variables:
PROJECT_SOURCE_DIR, <PROJECT-NAME>_SOURCE_DIR
Absolute path to the source directory for the project.
PROJECT_BINARY_DIR, <PROJECT-NAME>_BINARY_DIR
Absolute path to the binary directory for the project.
PROJECT_IS_TOP_LEVEL, <PROJECT-NAME>_IS_TOP_LEVEL
New in version 3.21.
Boolean value indicating whether the project is top-level.
Further variables are set by the optional arguments described in the following. If any of these
arguments is not used, then the corresponding variables are set to the empty string.
Options
The options are:
VERSION <version>
Optional; may not be used unless policy CMP0048 is set to NEW.
Takes a <version> argument composed of non-negative integer components, i.e.
<major>[.<minor>[.<patch>[.<tweak>]]], and sets the variables
• PROJECT_VERSION, <PROJECT-NAME>_VERSION
• PROJECT_VERSION_MAJOR, <PROJECT-NAME>_VERSION_MAJOR
• PROJECT_VERSION_MINOR, <PROJECT-NAME>_VERSION_MINOR
• PROJECT_VERSION_PATCH, <PROJECT-NAME>_VERSION_PATCH
• PROJECT_VERSION_TWEAK, <PROJECT-NAME>_VERSION_TWEAK.
New in version 3.12: When the project() command is called from the top-level CMakeLists.txt, then
the version is also stored in the variable CMAKE_PROJECT_VERSION.
DESCRIPTION <project-description-string>
New in version 3.9.
Optional. Sets the variables
• PROJECT_DESCRIPTION, <PROJECT-NAME>_DESCRIPTION
to <project-description-string>. It is recommended that this description is a relatively short
string, usually no more than a few words.
When the project() command is called from the top-level CMakeLists.txt, then the description is
also stored in the variable CMAKE_PROJECT_DESCRIPTION.
New in version 3.12: Added the <PROJECT-NAME>_DESCRIPTION variable.
HOMEPAGE_URL <url-string>
New in version 3.12.
Optional. Sets the variables
• PROJECT_HOMEPAGE_URL, <PROJECT-NAME>_HOMEPAGE_URL
to <url-string>, which should be the canonical home URL for the project.
When the project() command is called from the top-level CMakeLists.txt, then the URL also is
stored in the variable CMAKE_PROJECT_HOMEPAGE_URL.
LANGUAGES <language-name>...
Optional. Can also be specified without LANGUAGES keyword per the first, short signature.
Selects which programming languages are needed to build the project.
Supported languages are C, CXX (i.e. C++), CSharp (i.e. C#), CUDA, OBJC (i.e. Objective-C), OBJCXX
(i.e. Objective-C++), Fortran, HIP, ISPC, Swift, ASM, ASM_NASM, ASM_MARMASM, ASM_MASM, and ASM-ATT.
New in version 3.8: Added CSharp and CUDA support.
New in version 3.15: Added Swift support.
New in version 3.16: Added OBJC and OBJCXX support.
New in version 3.18: Added ISPC support.
New in version 3.21: Added HIP support.
New in version 3.26: Added ASM_MARMASM support.
If enabling ASM, list it last so that CMake can check whether compilers for other languages like C work
for assembly too.
By default C and CXX are enabled if no language options are given. Specify language NONE, or use the
LANGUAGES keyword and list no languages, to skip enabling any languages.
The variables set through the VERSION, DESCRIPTION and HOMEPAGE_URL options are intended for use as
default values in package metadata and documentation.
Code Injection
A number of variables can be defined by the user to specify files to include at different points during
the execution of the project() command. The following outlines the steps performed during a project()
call:
• New in version 3.15: For every project() call regardless of the project name, include the file named by
CMAKE_PROJECT_INCLUDE_BEFORE, if set.
• New in version 3.17: If the project() command specifies <PROJECT-NAME> as its project name, include the
file named by CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE, if set.
• Set the various project-specific variables detailed in the Synopsis and Options sections above.
• For the very first project() call only:
• If CMAKE_TOOLCHAIN_FILE is set, read it at least once. It may be read multiple times and it may also
be read again when enabling languages later (see below).
• Set the variables describing the host and target platforms. Language-specific variables might or
might not be set at this point. On the first run, the only language-specific variables that might be
defined are those a toolchain file may have set. On subsequent runs, language-specific variables
cached from a previous run may be set.
• New in version 3.24: Include each file listed in CMAKE_PROJECT_TOP_LEVEL_INCLUDES, if set. The
variable is ignored by CMake thereafter.
• Enable any languages specified in the call, or the default languages if none were provided. The
toolchain file may be re-read when enabling a language for the first time.
• New in version 3.15: For every project() call regardless of the project name, include the file named by
CMAKE_PROJECT_INCLUDE, if set.
• If the project() command specifies <PROJECT-NAME> as its project name, include the file 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.
New 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.
New 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 New 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 New 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 ...)
New 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.
New 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
New 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.
New 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.
New 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.
New 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.
New 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
New 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.
New 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. 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.
New 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.
New 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.
New 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>.
Note that generator expressions will not be used in OLD handling of policy CMP0003 or policy CMP0004.
• 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-buildsystem(7) manual for more on defining buildsystem properties.
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. When 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)
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.
This signature is for compatibility only. Prefer the PUBLIC or PRIVATE keywords instead.
Libraries and targets following LINK_PUBLIC are linked to, and are made part of the
INTERFACE_LINK_LIBRARIES. 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)
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. If policy CMP0022 is not NEW, then this mode also appends libraries
to the LINK_INTERFACE_LIBRARIES and its per-configuration equivalent.
This signature is for compatibility only. Prefer the INTERFACE mode instead.
Libraries specified as debug are wrapped in a generator expression to correspond to debug builds. If
policy CMP0022 is not NEW, the libraries are also appended to the LINK_INTERFACE_LIBRARIES_DEBUG property
(or to the properties corresponding to configurations listed in the DEBUG_CONFIGURATIONS global property
if it is set). Libraries specified as optimized are appended to the INTERFACE_LINK_LIBRARIES property.
If policy CMP0022 is not NEW, they are also appended to the LINK_INTERFACE_LIBRARIES property. Libraries
specified as general (or without any keyword) are treated as if specified for both debug and optimized.
Linking Object Libraries
New 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>
New 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
New 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
New 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.
New 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
New 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
New 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.
New 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.
New in version 3.3: Allow exporting targets with INTERFACE_SOURCES.
New 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
New 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
New 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>])
New 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.
New in version 3.26: This command records a configure-log try_compile 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_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>...]
[OUTPUT_VARIABLE <var>]
[COPY_FILE <fileName> [COPY_FILE_ERROR <var>]]
[<LANG>_STANDARD <std>]
[<LANG>_STANDARD_REQUIRED <bool>]
[<LANG>_EXTENSIONS <bool>]
)
New in version 3.25.
Try building an executable or static library from one or more source files (which one is determined by
the CMAKE_TRY_COMPILE_TARGET_TYPE variable). Build success returns TRUE and build failure returns FALSE
in <compileResultVar>.
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 INCLUDE_DIRECTORIES,
LINK_DIRECTORIES, and LINK_LIBRARIES are used.
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.
LINK_OPTIONS <options>...
New 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.
LOG_DESCRIPTION <text>
New 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
New in version 3.25.
The result will be stored in a normal variable rather than a cache entry.
The result variable 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 New 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>
New 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>
New 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>
New 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>
New 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
New 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>
New 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>
New 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>
New 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
New 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_LINK_SEARCH_START_STATIC
• CMAKE_LINK_SEARCH_END_STATIC
• CMAKE_MSVC_RUNTIME_LIBRARY
• CMAKE_POSITION_INDEPENDENT_CODE
• CMAKE_WATCOM_RUNTIME_LIBRARY
If CMP0056 is set to NEW, then CMAKE_EXE_LINKER_FLAGS is passed in as well.
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.
The current settings of CMP0065 and CMP0083 are 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.
New in version 3.6: Set the CMAKE_TRY_COMPILE_TARGET_TYPE variable to specify the type of target used for
the source file signature.
New 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.
New in version 3.24: The CMAKE_TRY_COMPILE_NO_PLATFORM_VARIABLES variable may be set to disable passing
platform variables into the test project.
New 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.
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>...]
)
New in version 3.25.
Try building an executable from one or more source files. Build success returns TRUE and build failure
returns FALSE in <compileResultVar>. If the build succeeds, this runs the executable and stores the exit
code in <runResultVar>. 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.
New 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>...]
[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>
New in version 3.25.
Report the output of stdout from running the executable in a given variable.
RUN_OUTPUT_STDERR_VARIABLE <var>
New in version 3.25.
Report the output of stderr from running the executable in a given variable.
WORKING_DIRECTORY <var>
New 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
New 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>
New 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>
New 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 New 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>
New 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 New 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>
New 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 New 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>
New 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 no argument is provided then the
current script is run using the current settings of the variables. 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 New 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>
New 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>
New in version 3.15.
Store in the <result-var> variable the ID assigned to this build by CDash.
HTTPHEADER <HTTP-header>
New 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>
New 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 New in version 3.3.
Suppress all non-error messages that would have otherwise been printed to the console.
Submit to CDash Upload API
New 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.
New in version 3.8: Added the RETRY_COUNT, RETRY_DELAY, QUIET options.
New in version 3.9: Added the HTTPHEADER option.
New in version 3.13: Added the RETURN_VALUE option.
New in version 3.14: Added the SUBMIT_URL option.
New 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_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_FIXTURE <regex>
New 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>
New in version 3.7.
Same as EXCLUDE_FIXTURE except only matching setup tests are excluded.
EXCLUDE_FIXTURE_CLEANUP <regex>
New in version 3.7.
Same as EXCLUDE_FIXTURE except only matching cleanup tests are excluded.
PARALLEL_LEVEL <level>
Specify a positive number representing the number of tests to be run in parallel.
RESOURCE_SPEC_FILE <file>
New in version 3.16.
Specify a resource specification file. See Resource Allocation for more information.
TEST_LOAD <threshold>
New 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>
New 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
New 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>
New 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>
New 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 New 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
New 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
New 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
New 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>
New 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 New 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 New 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>
New 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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