CMAKE-COMMANDS(7) CMake CMAKE-COMMANDS(7)
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).
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
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 file-
name has the following format: NNN-<name>.cmake, where NNN is
three digits used to apply collected scripts in a specific or-
der.
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 re-
sult 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 mes-
sage 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 com-
puter 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 de-
fault 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 speci-
fied, BOTH view is used.
64 Query the 64bit registry. On 32bit Windows, returns al-
ways 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 reg-
istry using view 32. For VALUE_NAMES and SUBKEYS sub-op-
tions, 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 reg-
istry using view 64. For VALUE_NAMES and SUBKEYS sub-op-
tions, 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 de-
fined. 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 suc-
cess, 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 exam-
ple, 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 refer-
ences in arguments are evaluated at the time the deferred call is exe-
cuted.
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(). Fur-
thermore, the given directory must not yet be finished process-
ing. 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 under-
score (_).
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 ele-
ments are its unevaluated arguments (any contained ; characters are in-
cluded 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 DIREC-
TORY 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 ${id})
message("Immediate Message")
set(deferred_message "Deferred Message")
prints:
Immediate Message
Deferred Message
The Cancelled Message is never printed because its command is canceled.
The deferred_message variable reference is not evaluated until the call
site, so it can be set after the deferred call is scheduled.
In order to evaluate variable references immediately when scheduling a
deferred call, wrap it using cmake_language(EVAL). However, note that
arguments will be re-evaluated in the deferred call, though that can be
avoided by using bracket arguments. For example:
set(deferred_message "Deferred Message 1")
set(re_evaluated [[${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 sup-
port 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() re-
quests. 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 vari-
able, 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 recom-
mended form is xxx_provide_dependency(), where xxx is the provider-spe-
cific part (e.g. vcpkg_provide_dependency(), conan_provide_depen-
dency(), 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 vari-
able 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 de-
pendency named depName, the provider must set depName_FOUND to
true if it fulfilled the request. If the provider returns with-
out 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() imple-
mentation 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 de-
clared arguments, they will be added with their default val-
ues.
• 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-insensi-
tively.
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() com-
mand.
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 ver-
sion meets any requirements for that dependency and is compati-
ble 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_<upper-
caseDepName> 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 arti-
facts. 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 ${MYCOMP_PROVIDER_INSTALL_DIR}
COMMAND_ERROR_IS_FATAL ANY
)
endmacro()
cmake_language(
SET_DEPENDENCY_PROVIDER mycomp_provide_dependency
SUPPORTED_METHODS FIND_PACKAGE
)
The user would then typically use the above file like so:
cmake -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=/path/to/mycomp_provider.cmake ...
The next example demonstrates a provider that accepts both methods, but
only handles one specific dependency. It enforces providing Google
Test using FetchContent, but leaves all other dependencies to be ful-
filled by CMake's built-in implementation. It accepts a few different
names, which demonstrates one way of working around projects that
hard-code an unusual or undesirable way of adding this particular de-
pendency to the build. The example also demonstrates how to use the
list() command to preserve variables that may be overwritten by a call
to FetchContent_MakeAvailable().
mycomp_provider.cmake
cmake_minimum_required(VERSION 3.24)
# Because we declare this very early, it will take precedence over any
# details the project might declare later for the same thing
include(FetchContent)
FetchContent_Declare(
googletest
GIT_REPOSITORY https://github.com/google/googletest.git
GIT_TAG e2239ee6043f73722e7aa812a459f54a28552929 # release-1.11.0
)
# Both FIND_PACKAGE and FETCHCONTENT_MAKEAVAILABLE_SERIAL methods provide
# the package or dependency name as the first method-specific argument.
macro(mycomp_provide_dependency method dep_name)
if("${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 "${googletest_BINARY_DIR}"
)
endif()
endif()
endmacro()
cmake_language(
SET_DEPENDENCY_PROVIDER mycomp_provide_dependency
SUPPORTED_METHODS
FIND_PACKAGE
FETCHCONTENT_MAKEAVAILABLE_SERIAL
)
The final example demonstrates how to modify arguments to a
find_package() call. It forces all such calls to have the QUIET key-
word. It uses the BYPASS_PROVIDER keyword to prevent calling the
provider command recursively for the same dependency.
mycomp_provider.cmake
cmake_minimum_required(VERSION 3.24)
macro(mycomp_provide_dependency method)
find_package(${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_vari-
able>.
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 ver-
sion it will stop processing the project and report an error. The op-
tional <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 poli-
cies 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 er-
ror 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() com-
mand. It is important to establish version and policy settings be-
fore invoking other commands whose behavior they may affect. See
also policy CMP0000.
Calling cmake_minimum_required() inside a function() limits some ef-
fects 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 dis-
couraged.
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 implic-
itly 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 in-
vokes
cmake_policy(VERSION 2.4[...<max>])
which enables compatibility features for CMake 2.4 and lower.
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 argu-
ments 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() com-
mand.
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 TAR-
GETS or FILES keywords of the install() command.
Changed in version 3.5: All keywords shall be unique. I.e. every key-
word shall only be specified once in either <options>, <one_value_key-
words> or <multi_value_keywords>. A warning will be emitted if unique-
ness 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>_UN-
PARSED_ARGUMENTS that will be undefined if all arguments were recog-
nized. 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 <pre-
fix>_KEYWORDS_MISSING_VALUES that will be undefined if all keywords re-
ceived values. This can be checked to see if there were keywords with-
out 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 unde-
fined 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 inter-
preted 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.
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 un-
derlying 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 sys-
tem (i.e. the host platform), not the target system. When
cross-compiling, if the path contains elements that are not repre-
sentable 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 com-
mand. 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 di-
rectory. 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 di-
rectory 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 di-
rectory-separator. The ()* characters are not part of the path.
directory-separator
The only recognized directory separator is a forward slash char-
acter /. If this character is repeated, it is treated as a sin-
gle 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-sepa-
rator. The filename is effectively the last item-name of the
path, so it can also be a hard link, symbolic link or a direc-
tory.
A filename can have an extension. By default, the extension is
defined as the sub-string beginning at the left-most period (in-
cluding the period) and until the end of the filename. In com-
mands that accept a LAST_ONLY keyword, LAST_ONLY changes the in-
terpretation to the sub-string beginning at the right-most pe-
riod.
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 re-
moved.
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 ex-
ample 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 key-
word. 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 sep-
arators, with a single / (/a///b --> /a/b).
3. Remove each solitary period (.) and any immediately following direc-
tory-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 fol-
lowing directory-separator (/a/b/../c --> a/c).
5. If there is a root-directory, remove any .. and any directory-sepa-
rators 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 di-
rectory 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-sep-
arator 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 multi-
ple 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 Win-
dows, 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 di-
rectory-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 fol-
lowing:
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 op-
tion. 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-spe-
cific 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
$ENV{PATH}. A search path will be converted to a cmake-style list sep-
arated by ; characters (on non-Windows platforms, this essentially
means : separators are replaced with ;). The result of the conversion
is stored in the <out-var> variable.
When the NORMALIZE option is specified, the path is normalized before
the conversion.
NOTE:
Unlike most other cmake_path() subcommands, the CONVERT subcommand
takes a literal string as input, not the name of a variable.
cmake_path(CONVERT <input> TO_NATIVE_PATH_LIST <out-var> [NORMALIZE])
Converts a cmake-style <input> path into a native path with plat-
form-specific slashes (\ on Windows hosts and / elsewhere). The input
can be a single path or a cmake-style list. A list will be converted
into a native search path (;-separated on Windows, :-separated on other
platforms). The result of the conversion is stored in the <out-var>
variable.
When the NORMALIZE option is specified, the path is normalized before
the conversion.
NOTE:
Unlike most other cmake_path() subcommands, the CONVERT subcommand
takes a literal string as input, not the name of a variable.
For example:
set(paths "/a/b/c" "/x/y/z")
cmake_path(CONVERT "${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 de-
fined 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 de-
sired behavior. When CMake needs to know which behavior to use it
checks for a setting specified by the project. If no setting is avail-
able 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 behav-
ior. 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 ma-
jor.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 compo-
nent separators, resulting in the ...<max> part being ignored and pre-
serving 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.
Setting Policies Explicitly
cmake_policy(SET CMP<NNNN> NEW)
cmake_policy(SET CMP<NNNN> 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 pro-
tect its parents and siblings. CMake also manages a new entry for
scripts loaded by include() and find_package() commands except when in-
voked 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)
cmake_policy(POP)
Each PUSH must have a matching POP to erase any changes. This is use-
ful to make temporary changes to policy settings. Calls to the
cmake_minimum_required(VERSION), cmake_policy(VERSION), or cmake_pol-
icy(SET) commands influence only the current top of the policy stack.
New in version 3.25: The block() and endblock() commands offer a more
flexible and more secure way to manage the policy stack. The pop action
is done automatically when the endblock() command is executed, so it
avoid to call the cmake_policy(POP) command before each return() com-
mand.
# 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 poli-
cies, the changes automatically propagate up through callers until they
reach the closest nested policy stack entry.
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@ or ${VAR} in the input file content. Each
variable reference will be replaced with the current value of the vari-
able, 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 af-
ter 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 #cmakede-
fine01 VAR ... 0 or #cmakedefine01 VAR ... 0, which may lead to unde-
fined 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 # char-
acter and the cmakedefine or cmakedefine01 words. This whitespace in-
dentation 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 gener-
ated 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 per-
missions-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 <per-
missions> 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 ${VAR} syntax.
NEWLINE_STYLE <style>
Specify the newline style for the output file. Specify UNIX or
LF for \n newlines, or specify DOS, WIN32, or CRLF for \r\n new-
lines. This option may not be used with COPYONLY.
Example
Consider a source tree containing a foo.h.in file:
#cmakedefine FOO_ENABLE
#cmakedefine FOO_STRING "@FOO_STRING@"
An adjacent CMakeLists.txt may use configure_file to configure the
header:
option(FOO_ENABLE "Enable Foo" ON)
if(FOO_ENABLE)
set(FOO_STRING "foo")
endif()
configure_file(foo.h.in foo.h @ONLY)
This creates a foo.h in the build directory corresponding to this
source directory. If the FOO_ENABLE option is on, the configured file
will contain:
#define FOO_ENABLE
#define FOO_STRING "foo"
Otherwise it will contain:
/* #undef FOO_ENABLE */
/* #undef FOO_STRING */
One may then use the include_directories() command to specify the out-
put directory as an include directory:
include_directories(${CMAKE_CURRENT_BINARY_DIR})
so that sources may include the header as #include <foo.h>.
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 <con-
dition>.
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 compatibil-
ity only. If used it must be a verbatim repeat of the <loop_var> argu-
ment 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 compatibil-
ity 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 compatibil-
ity 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 sin-
gle standard error pipe is used for all processes.
Options:
COMMAND
A child process command line.
CMake executes the child process using operating system APIs di-
rectly:
• 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.)
If a sequential execution of multiple commands is required, use
multiple execute_process() calls 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 RE-
SULT_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 ar-
guments. Each entry will be an integer return code from the
corresponding child or a string describing an error condition.
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.
INPUT_FILE, OUTPUT_FILE, ERROR_FILE
The file named will be attached to the standard input of the
first process, standard output of the last process, or standard
error of all processes, respectively.
New in version 3.3: If the same file is named for both output
and error then it will be used for both.
OUTPUT_QUIET, ERROR_QUIET
The standard output or standard error results will be quietly
ignored.
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 out-
put is encoded in the same way as CMake's internal encod-
ing (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 consis-
tency with the UTF-8 RFC naming convention.
ECHO_OUTPUT_VARIABLE, ECHO_ERROR_VARIABLE
New in version 3.18.
The standard output or standard error will not be exclusively
redirected to the configured variables.
The output will be duplicated, it will be sent into the config-
ured variables and also on standard output or standard error.
This is analogous to the tee Unix command.
COMMAND_ERROR_IS_FATAL <ANY|LAST>
New in version 3.19.
The option following COMMAND_ERROR_IS_FATAL determines the be-
havior 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 ear-
lier in the list will not cause a fatal error.
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.
The execute_process() command is a newer more powerful version of
exec_program(), but the old command has been kept for compatibility.
Both commands run while CMake is processing the project prior to build
system generation. Use add_custom_target() and add_custom_command() to
create custom commands that run at build time.
file
File manipulation command.
This command is dedicated to file and path manipulation requiring ac-
cess 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 <vari-
able>. Optionally start from the given <offset> and read at most
<max-in> bytes. The HEX option causes data to be converted to a hexa-
decimal 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 <vari-
able>. 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 in-
stead of terminating at them.
NO_HEX_CONVERSION
Intel Hex and Motorola S-record files are automatically con-
verted 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 en-
codings are: UTF-8, UTF-16LE, UTF-16BE, UTF-32LE, UTF-32BE. If
the ENCODING option is not provided and the file has a Byte Or-
der 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
[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>...]]
)
New in version 3.16.
Recursively get the list of libraries depended on by the given 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 gener-
ated by the install(RUNTIME_DEPENDENCY_SET) command, or from code pro-
vided by the project via install(CODE) or install(SCRIPT). For exam-
ple:
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 de-
pendencies.
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 infor-
mation. Dependencies are conflicting if two files with the same
name are found in two different directories. The list of file-
names that conflict are stored in <conflicting_deps_pre-
fix>_FILENAMES. For each filename, the list of paths that were
found for that filename are stored in <conflicting_deps_pre-
fix>_<filename>.
EXECUTABLES <executable_files>
List of executable files to read for dependencies. These are ex-
ecutables 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 unde-
fined behavior.
LIBRARIES <library_files>
List of library files to read for dependencies. These are li-
braries that are typically created with add_library(SHARED), but
they do not have to be created by CMake. Specifying STATIC li-
braries, 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 depen-
dency 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 direc-
tories 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 EXECUTA-
BLES files. On other platforms, it has no effect. This is typi-
cally (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 li-
braries 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 di-
rectory. The filtering works as follows:
1. If the not-yet-resolved dependency matches any of the PRE_IN-
CLUDE_REGEXES, steps 2 and 3 are skipped, and the dependency resolu-
tion proceeds to step 4.
2. If the not-yet-resolved dependency matches any of the PRE_EX-
CLUDE_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) re-
cursively resolves that library's own dependencies. Otherwise, reso-
lution 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 de-
pendency.
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 dependen-
cies, and file(GET_RUNTIME_DEPENDENCIES) recursively resolves that
library's own dependencies.
Different platforms have different rules for how dependencies are re-
solved. 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 li-
brary 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 direc-
tories from which it pulls dependencies).
5. Otherwise, the dependency is unresolved.
On Windows platforms, library resolution works as follows:
1. The dependent DLL name is converted to lowercase. 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_IN-
CLUDE_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.)
Please note that the directory portion of any resolved DLLs retains
its casing and is not converted to lowercase. Only the filename por-
tion is converted.
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 de-
pending 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 de-
pendency 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 re-
solved to that file. In this case, a warning is not issued, because
searching other directories is a normal part of Windows library res-
olution.
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 @exe-
cutable_path/ with the directory of the executable yields an exist-
ing 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 @exe-
cutable_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 replac-
ing @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 automati-
cally 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_DEPEN- │ CMAKE_GET_RUNTIME_DEPEN- │
│DENCIES_PLATFORM │ DENCIES_TOOL │
├─────────────────────────┼──────────────────────────┤
│linux+elf │ objdump │
├─────────────────────────┼──────────────────────────┤
│windows+pe │ dumpbin │
├─────────────────────────┼──────────────────────────┤
│windows+pe │ objdump │
├─────────────────────────┼──────────────────────────┤
│macos+macho │ otool │
└─────────────────────────┴──────────────────────────┘
If this variable is not specified, it is determined automati-
cally by system introspection.
CMAKE_GET_RUNTIME_DEPENDENCIES_COMMAND
Determines the path to the tool to use for dependency resolu-
tion. 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 up-
date 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 al-
ready 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 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] ])
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. 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 af-
ter 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 expres-
sions such as $<CONFIG> to specify a configuration-specific out-
put file name. Multiple configurations may generate the same
output file only if the generated content is identical. Other-
wise, the <output-file> must evaluate to an unique name for each
configuration.
Changed in version 3.10: A relative path (after evaluating gen-
erator 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 expres-
sions that require a target for evaluation (e.g. $<COMPILE_FEA-
TURES:...>, $<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). Gener-
ated 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 new-
lines.
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 reg-
ular 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 underly-
ing filesystem is case-sensitive (both filenames and globbing expres-
sions 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 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 sym-
links 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 re-
sult 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, also 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 <new-
name>, 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 other-
wise. 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 RE-
SULT <result> is used, the result variable will be set to NO_RE-
PLACE. Otherwise, an error is emitted.
file(COPY_FILE <oldname> <newname>
[RESULT <result>]
[ONLY_IF_DIFFERENT])
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 other-
wise. 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).
This sub-command has some similarities to configure_file() with the
COPYONLY option. An important difference is that configure_file() cre-
ates 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 depen-
dency.
See also the file(COPY) sub-command just below which provides further
file-copying capabilities.
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.
The COPY signature copies files, directories, and symlinks to a desti-
nation 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).
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 reso-
lution is stripped of the directory, leaving only the filename, meaning
that the new symlink points to a file in the same directory as the sym-
link. This feature is useful on some Unix systems, where libraries are
installed as a chain of symlinks with version numbers, with less spe-
cific versions pointing to more specific versions. FOLLOW_SYM-
LINK_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 directo-
ries 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 mes-
sages, and NO_SOURCE_PERMISSIONS is default.
Installation scripts generated by the install() command use this signa-
ture (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 <vari-
able> 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.
This subcommand queries 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 re-
solve 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 sym-
bolic link instead. Hard links require that original exists and is a
file, not a directory. If <linkname> already exists, it will be over-
written.
The <result> variable, if specified, receives the status of the opera-
tion. 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 emit-
ted.
Specifying COPY_ON_ERROR enables copying the file as a fallback if cre-
ating 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 di-
rectories.
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 sym-
links resolved.
BASE_DIRECTORY <dir>
If the provided <path> is a relative path, it is evaluated rela-
tive 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 ob-
tained from environment variables. On Windows, the USERPROFILE
environment variable is used, falling back to the HOME environ-
ment variable if USERPROFILE is not defined. On all other plat-
forms, only HOME is used.
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 / else-
where).
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 actu-
ally 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 opera-
tion 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 ele-
ment 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 operation. Suboption can be repeated several
times.
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 vari-
able 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 di-
rectory, if the NETRC level is OPTIONAL or REQUIRED. If this op-
tion is not specified, the value of the CMAKE_NETRC_FILE vari-
able 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 spec-
ified, 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 ALGO=<value>
Verify that the downloaded content hash matches the expected value,
where ALGO is one of the algorithms supported by file(<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 omit-
ted 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. File will be locked for scope defined by
GUARD option (default value is PROCESS). RELEASE option can be used to
unlock file explicitly. If option TIMEOUT is not specified CMake will
wait until lock succeed or until fatal error occurs. If TIMEOUT is set
to 0 lock will be tried once and result will be reported immediately.
If TIMEOUT is not 0 CMake will try to lock file for the period speci-
fied by <seconds> value. Any errors will be interpreted as fatal if
there is no RESULT_VARIABLE option. Otherwise result will be stored in
<variable> and will be 0 on success or 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 in-
stances sharing some modifiable resources. Similar logic applied to DI-
RECTORY option - locking parent directory doesn't prevent other LOCK
commands to lock any child directory or file.
Trying to lock file twice is not allowed. Any intermediate directories
and file itself will be created if they not exist. GUARD and TIMEOUT
options ignored on 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 direc-
tories, 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 com-
pression. The other formats use no compression by default, but can be
directed to do so with the COMPRESSION option. Valid values for <com-
pression> 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.
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 ex-
tract 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 cre-
ated 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 suf-
fix, 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 loca-
tions. The ENV var sub-option reads paths from a system envi-
ronment 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, oth-
erwise 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. New in version 3.12: 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. Specifically,
look in the <PackageName>_ROOT CMake variable and the
<PackageName>_ROOT environment variable. 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 <CurrentPack-
age>_ROOT, ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT,
ENV{<ParentPackage>_ROOT}, etc. This can be skipped if NO_PACK-
AGE_ROOT_PATH is passed or by setting the
CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE. See policy CMP0074.
• <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: <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.
6. Search cmake variables defined in the Platform files for the current
system. The searching of CMAKE_INSTALL_PREFIX and CMAKE_STAG-
ING_PREFIX can be skipped if NO_CMAKE_INSTALL_PREFIX is passed or by
setting the CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these loca-
tions 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 directo-
ries 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-root-
ing, because that variable is always a path on the host system. By de-
fault the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one di-
rectory to use as a prefix. Setting CMAKE_SYSROOT also has other ef-
fects. 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 over-
ridden 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-spe-
cific 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 suf-
fix, 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 loca-
tions. The ENV var sub-option reads paths from a system envi-
ronment 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, oth-
erwise the search will be attempted again the next time find_li-
brary 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. New in version 3.12: 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. Specifically,
look in the <PackageName>_ROOT CMake variable and the
<PackageName>_ROOT environment variable. 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 <CurrentPack-
age>_ROOT, ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT,
ENV{<ParentPackage>_ROOT}, etc. This can be skipped if NO_PACK-
AGE_ROOT_PATH is passed or by setting the
CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE. See policy CMP0074.
• <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: <prefix>/lib/<arch> if
CMAKE_LIBRARY_ARCHITECTURE is set, and <prefix>/lib for each <pre-
fix>/[s]bin in PATH, and <entry>/lib for other entries in PATH.
6. Search cmake variables defined in the Platform files for the current
system. The searching of CMAKE_INSTALL_PREFIX and CMAKE_STAG-
ING_PREFIX can be skipped if NO_CMAKE_INSTALL_PREFIX is passed or by
setting the CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these loca-
tions 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 directo-
ries 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-root-
ing, because that variable is always a path on the host system. By de-
fault the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one di-
rectory to use as a prefix. Setting CMAKE_SYSROOT also has other ef-
fects. 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 over-
ridden 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-spe-
cific 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 direc-
tory 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.
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_SUF-
FIX}/. 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 lan-
guages 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 lan-
guages 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<Package-
Name>.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 pro-
cessed 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 some-
thing 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 <lowercasePacka-
geName>-config.cmake or <PackageName>Config.cmake. It will also
look for <lowercasePackageName>-config-version.cmake or <Packa-
geName>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 compli-
cated 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 sig-
natures.
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, ex-
cept that the search logic is by-passed and the component infor-
mation 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 re-
verse 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 sig-
nature 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 op-
tion 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 sat-
isfied, the package overall is considered to be not found. If the RE-
QUIRED option is also present, this is treated as a fatal error, other-
wise execution still continues. As a form of shorthand, if the RE-
QUIRED 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 consid-
ered 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 inter-
pret the component information given to it, but it should follow the
expectations stated above. For calls where no components are speci-
fied, 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-de-
fined 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 im-
ported targets to a global scope in the importing project. Alterna-
tively, 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 op-
tion is incompatible with the specification of a version range.
If no [version] and/or component list is given to a recursive invoca-
tion inside a find-module, the corresponding arguments are forwarded
automatically from the outer call (including the EXACT flag for [ver-
sion]). Version support is currently provided only on a pack-
age-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 op-
tions 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 re-
placement set of possible configuration file names may be given using
the CONFIGS option. The Config Mode Search Procedure is specified be-
low. 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 en-
couraged to name and install them such that the Config Mode Search Pro-
cedure outlined below will find them without requiring use of addi-
tional options.
Config Mode Search Procedure
NOTE:
When Config mode is used, this search procedure is applied regard-
less 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 redi-
rect find_package() calls to content already provided by the project.
If no config package file is found in that location, the search pro-
ceeds with the logic described below.
CMake constructs a set of possible installation prefixes for the pack-
age. Under each prefix several directories are searched for a configu-
ration file. The tables below show the directories searched. Each en-
try 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 │
├────────────────────────────────────────────────────────────┼────────────┤
│<pre- │ W │
│fix>/<name>*/(cmake|CMake)/ │ │
├────────────────────────────────────────────────────────────┼────────────┤
│<pre- │ W │
│fix>/<name>*/(cmake|CMake)/<name>*/ │ │
│[1] │ │
├────────────────────────────────────────────────────────────┼────────────┤
│<pre- │ U │
│fix>/(lib/<arch>|lib*|share)/cmake/<name>*/ │ │
├────────────────────────────────────────────────────────────┼────────────┤
│<prefix>/(lib/<arch>|lib*|share)/<name>*/ │ U │
├────────────────────────────────────────────────────────────┼────────────┤
│<pre- │ U │
│fix>/(lib/<arch>|lib*|share)/<name>*/(cmake|CMake)/ │ │
├────────────────────────────────────────────────────────────┼────────────┤
│<pre- │ W/U │
│fix>/<name>*/(lib/<arch>|lib*|share)/cmake/<name>*/ │ │
├────────────────────────────────────────────────────────────┼────────────┤
│<prefix>/<name>*/(lib/<arch>|lib*|share)/<name>*/ │ W/U │
├────────────────────────────────────────────────────────────┼────────────┤
│<pre- │ W/U │
│fix>/<name>*/(lib/<arch>|lib*|share)/<name>*/(cmake|CMake)/ │ │
└────────────────────────────────────────────────────────────┴────────────┘
[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>.frame- │ A │
│work/Resources/ │ │
├───────────────────────────┼────────────┤
│<prefix>/<name>.frame- │ A │
│work/Resources/CMake/ │ │
├───────────────────────────┼────────────┤
│<prefix>/<name>.frame- │ A │
│work/Versions/*/Resources/ │ │
├───────────────────────────┼────────────┤
│<prefix>/<name>.frame- │ A │
│work/Versions/*/Re- │ │
│sources/CMake/ │ │
├───────────────────────────┼────────────┤
│<prefix>/<name>.app/Con- │ A │
│tents/Resources/ │ │
├───────────────────────────┼────────────┤
│<prefix>/<name>.app/Con- │ A │
│tents/Resources/CMake/ │ │
└───────────────────────────┴────────────┘
In all cases the <name> is treated as case-insensitive and corre-
sponds to any of the names specified (<PackageName> or names given
by NAMES).
Paths with lib/<arch> are enabled if the
CMAKE_LIBRARY_ARCHITECTURE variable is set. lib* includes one or
more of the values lib64, lib32, libx32 or lib (searched in that
order).
• Paths with lib64 are searched on 64 bit platforms if the
FIND_LIBRARY_USE_LIB64_PATHS property is set to TRUE.
• Paths with lib32 are searched on 32 bit platforms if the
FIND_LIBRARY_USE_LIB32_PATHS property is set to TRUE.
• Paths with libx32 are searched on platforms using the x32 ABI if the
FIND_LIBRARY_USE_LIBX32_PATHS property is set to TRUE.
• The lib path is 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 mean-
ingful on Windows platforms and will be ignored on other ones. When not
specified, the TARGET view is used when the CMP0134 policy is NEW. Re-
fer 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 in-
stallation directory. Those marked with (U) are intended for installa-
tions on UNIX platforms where the prefix is shared by multiple pack-
ages. This is merely a convention, so all (W) and (U) directories are
still searched on all platforms. Directories marked with (A) are in-
tended 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. New in version 3.12: Search paths specified in the
<PackageName>_ROOT CMake variable and the <PackageName>_ROOT envi-
ronment variable, where <PackageName> is the package to be found.
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. See policy CMP0074.
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 lo-
cation 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 direc-
tories:
• 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 set-
ting 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 directo-
ries 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-root-
ing, because that variable is always a path on the host system. By de-
fault the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one di-
rectory to use as a prefix. Setting CMAKE_SYSROOT also has other ef-
fects. 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 over-
ridden 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-spe-
cific 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 vari-
able 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 ver-
sion of the package that claims compatibility with the requested ver-
sion (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 corre-
sponding version file is located next to it and named either <con-
fig-file>-version.cmake or <config-file>Version.cmake. If no such ver-
sion 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 de-
fined:
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 de-
scribed 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 mul-
tiple 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 op-
tional
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 de-
scribed 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 sup-
ported 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 re-
quest 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 con-
figuration file may set <PackageName>_FOUND to false to tell find_pack-
age 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 suf-
fix, 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 loca-
tions. The ENV var sub-option reads paths from a system envi-
ronment 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, oth-
erwise 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. New in version 3.12: 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. Specifically,
look in the <PackageName>_ROOT CMake variable and the
<PackageName>_ROOT environment variable. 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 <CurrentPack-
age>_ROOT, ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT,
ENV{<ParentPackage>_ROOT}, etc. This can be skipped if NO_PACK-
AGE_ROOT_PATH is passed or by setting the
CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE. See policy CMP0074.
• <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: <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.
6. Search cmake variables defined in the Platform files for the current
system. The searching of CMAKE_INSTALL_PREFIX and CMAKE_STAG-
ING_PREFIX can be skipped if NO_CMAKE_INSTALL_PREFIX is passed or by
setting the CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these loca-
tions 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 directo-
ries 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-root-
ing, because that variable is always a path on the host system. By de-
fault the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one di-
rectory to use as a prefix. Setting CMAKE_SYSROOT also has other ef-
fects. 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 over-
ridden 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-spe-
cific 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 suf-
fix, 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 loca-
tions. The ENV var sub-option reads paths from a system envi-
ronment 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, oth-
erwise 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. New in version 3.12: 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. Specifically,
look in the <PackageName>_ROOT CMake variable and the
<PackageName>_ROOT environment variable. 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 <CurrentPack-
age>_ROOT, ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT,
ENV{<ParentPackage>_ROOT}, etc. This can be skipped if NO_PACK-
AGE_ROOT_PATH is passed or by setting the
CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE. See policy CMP0074.
• <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.
• On Windows hosts no extra search paths are included
6. Search cmake variables defined in the Platform files for the current
system. The searching of CMAKE_INSTALL_PREFIX and CMAKE_STAG-
ING_PREFIX can be skipped if NO_CMAKE_INSTALL_PREFIX is passed or by
setting the CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these loca-
tions 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 directo-
ries 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-root-
ing, because that variable is always a path on the host system. By de-
fault the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one di-
rectory to use as a prefix. Setting CMAKE_SYSROOT also has other ef-
fects. 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 over-
ridden 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-spe-
cific 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 direc-
tory 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> ar-
gument. 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 si-
multaneously setting the iteration variables as follows:
• if the only loop_var given, then it sets a series of loop_var_N vari-
ables 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> argu-
ment. 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 poli-
cies 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-lower-
case 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 modi-
fied 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
• endfunction()
• return()
get_cmake_property
Get a global property of the CMake instance.
get_cmake_property(<var> <property>)
Gets a global property from the CMake instance. The value of the
<property> is stored in the variable <var>. If the property is not
found, <var> will be set to NOTFOUND. See the cmake-properties(7) man-
ual for available properties.
See also the get_property() command GLOBAL option.
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.
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 re-
trieve 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 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
cmake_path() command, except REALPATH now offered by file(REAL_PATH)
command and PROGRAM now available in separate_arguments(PROGRAM) com-
mand.
Changed in version 3.24: The undocumented feature offering the capabil-
ity 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.
get_property
Get a property.
get_property(<variable>
<GLOBAL |
DIRECTORY [<dir>] |
TARGET <target> |
SOURCE <source>
[DIRECTORY <dir> | TARGET_DIRECTORY <target>] |
INSTALL <file> |
TEST <test> |
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 prop-
erty. 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 rela-
tive 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> di-
rectory's scope. CMake must already know about the di-
rectory, either by having added it through a call to
add_subdirectory() or <dir> being the top level direc-
tory. Relative paths are treated as relative to the cur-
rent source directory.
New in version 3.19: <dir> may reference a binary direc-
tory.
TARGET_DIRECTORY <target>
The source file property will be read from the directory
scope in which <target> was created (<target> must there-
fore 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.
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 re-
turned, 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 indi-
cating 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 docu-
mentation is requested for a property that has not been defined NOT-
FOUND is returned.
NOTE:
The GENERATED source file property may be globally visible. See its
documentation for details.
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 com-
mands in the if block are executed. Otherwise, optional elseif blocks
are processed in the same way. Finally, if no condition is true, com-
mands in the optional else block are executed.
Per legacy, the else() and endif() commands admit an optional <condi-
tion> 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, el-
seif 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 num-
ber (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 ap-
plies.
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 hap-
pens to be a variable name that is affected by CMP0054's be-
havior.
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 exam-
ples. 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 cre-
ated 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 mat-
ter. 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 some-
Name exists. In comparison, the expression if(DEFINED
CACHE{someName}) will only evaluate to true if a cache vari-
able someName exists. Both expressions need to be tested if
you need to know whether a non-cache variable exists: if(DE-
FINED 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. 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.
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-to-directory)
True if the given name is a directory. Behavior is well-defined
only for full paths.
if(IS_SYMLINK file-name)
True if the given name is a symbolic link. Behavior is well-de-
fined 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 rela-
tive.
• 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 is a valid number
and less than that on the right.
if(<variable|string> GREATER <variable|string>)
True if the given string or variable's value is a valid number
and greater than that on the right.
if(<variable|string> EQUAL <variable|string>)
True if the given string or variable's value is a valid number
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
is a valid number 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
is a valid number 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 lexicographi-
cally 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 lexicographi-
cally 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 lexicographi-
cally 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 vari-
able 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 com-
parison (version format is major[.minor[.patch[.tweak]]], omit-
ted 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 com-
parison (version format is major[.minor[.patch[.tweak]]], omit-
ted 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 for-
ward 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 follow-
ing 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 con-
stant.
Automatic evaluation applies in the other cases whenever the above-doc-
umented 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 oth-
erwise 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 in-
dependently 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 derefer-
enced.
Changed in version 3.1: To prevent ambiguity, potential variable or
keyword names can be specified in a Quoted Argument or a Bracket Argu-
ment. 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 Ref-
erences. 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 RE-
SULT_VARIABLE is given the variable <var> will be set to the full file-
name which has been included or NOTFOUND if it failed.
If a module is specified instead of a file, the file with name <module-
name>.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 direc-
tory, 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 pro-
cessed for the applicable scope (see below). This provides functional-
ity similar to the include guards commonly used in source headers or to
the #pragma once directive. If the current file has been processed pre-
viously for the applicable scope, the effect is as though return() had
been called. Do not call this command from inside a function being de-
fined 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 be-
low. 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 cur-
rent 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
List operations.
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 actu-
ally defined in a parent scope. To propagate the results of these op-
erations upwards, use set() with PARENT_SCOPE, set() with CACHE INTER-
NAL, 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) cre-
ates 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 macro arguments are
not variables, and therefore cannot be used in LIST commands.)
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 in-
dexed 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 JOIN operator
from string() command.
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 <be-
gin>+<length> then the remaining elements of the list starting at <be-
gin> 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 ap-
pended 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 expres-
sion.
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 vari-
able 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 transfor-
mation.
<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> ...)
TOUPPER, TOLOWER: Convert each element of the list to upper, lower
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 REGEX REPLACE from string() command).
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, <SE-
LECTOR> 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 strver-
scmp(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 compar-
ison 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 poli-
cies 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 argu-
ments 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 argu-
ment. Referencing to ${ARGV#} arguments beyond ${ARGC} have undefined
behavior. Checking that ${ARGC} is greater than # is the only way to
ensure that ${ARGV#} was passed to the function as an extra argument.
Macro vs Function
The macro command is very similar to the function() command. Nonethe-
less, there are a few important differences.
In a function, ARGN, ARGC, ARGV and ARGV0, ARGV1, ... are true vari-
ables in the usual CMake sense. In a macro, they are not, they are
string replacements much like the C preprocessor would do with a macro.
This has a number of consequences, as explained in the Argument Caveats
section below.
Another difference between macros and functions is the control flow. A
function is executed by transferring control from the calling statement
to the function body. A macro is executed as if the macro body were
pasted in place of the calling statement. This has the consequence
that a return() in a macro body does not just terminate execution of
the macro; rather, control is returned from the scope of the macro
call. To avoid confusion, it is recommended to avoid return() in
macros altogether.
Unlike a function, the CMAKE_CURRENT_FUNCTION,
CMAKE_CURRENT_FUNCTION_LIST_DIR, CMAKE_CURRENT_FUNCTION_LIST_FILE,
CMAKE_CURRENT_FUNCTION_LIST_LINE variables are not set for a macro.
Argument Caveats
Since ARGN, ARGC, ARGV, ARGV0 etc. are not variables, you will NOT be
able to use commands like
if(ARGV1) # ARGV1 is not a variable
if(DEFINED ARGV2) # ARGV2 is not a variable
if(ARGC GREATER 2) # ARGC is not a variable
foreach(loop_var IN LISTS ARGN) # ARGN is not a variable
In the first case, you can use if(${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 exist-
ing 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.
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 un-
less the show advanced option is on. In script mode, the ad-
vanced/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 ad-
vanced/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 re-
sulting value. The result of the expression must be representable as a
64-bit signed integer.
The mathematical expression must be given as a string (i.e. enclosed in
double quotation marks). An example is "5 * (10 + 13)". Supported op-
erators 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" ...)
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 in-
fluences 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, re-
spectively, 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 inter-
ested in. Ideally these should be concise, no more than a sin-
gle 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 de-
tails. 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 lev-
els.
The CMake command-line tool displays STATUS to TRACE messages on stdout
with the message preceded by two hyphens and a space. All other mes-
sage 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.exam-
ple]. The content between the square brackets is obtained by convert-
ing 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 con-
text 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 per-
formed.
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 re-
ported 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 ex-
ample:
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
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 op-
tion 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, de-
ferred 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 ex-
panded 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 be-
low.
The PROPAGATE option can be very useful in conjunction with the
block() command. A return() will propagate the specified vari-
ables 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()
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 en-
tire command line must be passed as one string in the argument <args>.
The exact parsing rules depend on the operating system. They are spec-
ified by the <mode> argument which must be one of the following key-
words:
UNIX_COMMAND
Arguments are separated by unquoted whitespace. Both sin-
gle-quote and double-quote pairs are respected. A backslash es-
capes 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 run-
time 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 ar-
ticle 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 Win-
dows. 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, com-
mand-line arguments will be split as well and stored in <vari-
able>.
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 interac-
tion 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.
Zero arguments will cause normal variables to be unset. See the
unset() command to unset variables explicitly.
Set Normal Variable
set(<variable> <value>... [PARENT_SCOPE])
Sets the given <variable> in the current function or directory scope.
If the PARENT_SCOPE option is given the variable will be set in the
scope above the current scope. Each new directory or function() com-
mand creates a new scope. A scope can also be created with the block()
command. This command will set the value of a variable into the parent
directory, calling function or encompassing scope (whichever is appli-
cable 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) com-
mands to update the parent scope.
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 rel-
ative 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 environ-
ment variable.
Arguments after <value> are ignored. If extra arguments are found, then
an author warning is issued.
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.
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> ...] |
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() com-
mand.
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.
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 direc-
tory.
TARGET_DIRECTORY <targets>...
The source file property will be set in each of the di-
rectory 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 directo-
ries.
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 may name zero or more existing tests. See also the
set_tests_properties() command.
Test property values may be specified using generator expres-
sions for tests created by the add_test(NAME) signature.
CACHE Scope must name zero or more cache existing 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 ex-
isting 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 prop-
erty 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 com-
mand will behave as though APPEND or APPEND_STRING had not been given.
See the cmake-properties(7) manual for a list of properties in each
scope.
NOTE:
The GENERATED source file property may be globally visible. See its
documentation for details.
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 sup-
plied <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 charac-
ters. The index stored in <output_variable> will also be counted in
bytes, so strings containing multi-byte characters may lead to unex-
pected results.
string(REPLACE <match_string>
<replace_string> <output_variable>
<input> [<input>...])
Replace all occurrences of <match_string> in the <input> with <re-
place_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 <out-
put_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 subex-
pressions of the match using \1, \2, ..., \9. Note that two back-
slashes (\\1) are required in CMake code to get a backslash through ar-
gument 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, in-
cluding e.g. if(MATCHES), save subgroup matches in the vari-
ables 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 alter-
natively 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 charac-
ters 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 exer-
cised 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 representa-
tion 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 un-
derscore 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 al-
phabet 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 speci-
fiers:
%% 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.
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 representa-
tion 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 <er-
ror-variable> and the <out-var> will be set to <member|index>-[<mem-
ber|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 <er-
ror-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 ele-
ment 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.
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 in-
stead of a normal variable. Note that when evaluating Variable Refer-
ences 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.
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.
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.
variable_watch
Watch the CMake variable for change.
variable_watch(<variable> [<command>])
If the specified <variable> changes and no <command> is given, a mes-
sage will be printed to inform about the change.
If <command> is given, this command will be executed instead. The com-
mand 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, UN-
KNOWN_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 cur-
rently processed file (that is, current_list_file) last.
Note that for some accesses such as list(APPEND), the watcher is exe-
cuted 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 ex-
isted.
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> argu-
ment. 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 di-
rectory property for the current CMakeLists file. They are also added
to the COMPILE_DEFINITIONS target property for each target in the cur-
rent CMakeLists file.
Definitions are specified using the syntax VAR or VAR=value. Func-
tion-style definitions are not supported. CMake will automatically es-
cape the value correctly for the native build system (note that CMake
language syntax may require escapes to specify some values).
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.
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.
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 accumulat-
ing 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 us-
ing 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 and all warnings as errors
add_compile_options(/W4 /WX)
else()
# lots of warnings and all warnings as errors
add_compile_options(-Wall -Wextra -pedantic -Werror)
endif()
See Also
This command can be used to add any options. However, for adding pre-
processor 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.
The source file property COMPILE_OPTIONS adds options to one source
file.
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 out-
put:
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]
[VERBATIM] [APPEND] [USES_TERMINAL]
[COMMAND_EXPAND_LISTS])
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 gener-
ate 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
two 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). In makefile terms this creates a new tar-
get in the following form:
OUTPUT: MAIN_DEPENDENCY DEPENDS
COMMAND
The options are:
APPEND Append the COMMAND and DEPENDS option values to the custom com-
mand 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 ex-
pression, the output specified by the current call must match in
at least one configuration after evaluating generator expres-
sions. In this case, the appended commands and dependencies ap-
ply 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 cur-
rent 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 byprod-
ucts 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 re-
stricted set of generator expressions. Target-dependent expres-
sions are not permitted.
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 back-
ward 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 be-
fore 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 us-
ing 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 depen-
dency 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.
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() com-
mand) 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 cur-
rent 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 ex-
pressions.
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_DIRECTO-
RIES>,;-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 corre-
sponding 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. Depen-
dencies 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.
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 specify-
ing it as its main dependency. A compile command (i.e. for a li-
brary or an executable) counts as an implicit main dependency
which gets silently overwritten by a custom command specifica-
tion.
OUTPUT Specify the output files the command is expected to produce. If
an output name is a relative path it will be interpreted rela-
tive to the build tree directory corresponding to the current
source directory. 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.
New in version 3.20: Arguments to OUTPUT may use a restricted
set of generator expressions. Target-dependent expressions are
not permitted.
USES_TERMINAL
New in version 3.2.
The command will be given direct access to the terminal if pos-
sible. 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 direc-
tory.
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 com-
mand. It is usually emitted by the custom command itself. This
keyword may only be used if the generator supports it, as de-
tailed 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 reg-
ular 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 IM-
PLICIT_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 DEP-
FILE 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.
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 ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
VERBATIM)
add_library(myLib out.c)
adds a custom command to run someTool to generate out.c and then com-
pile the generated source as part of a library. The generation rule
will re-run whenever in.txt changes.
New in version 3.20: One may use generator expressions to specify
per-configuration outputs. For example, the code:
add_custom_command(
OUTPUT "out-$<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.
Build Events
The second signature adds a custom command to a target such as a li-
brary 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] [USES_TERMINAL]
[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 direc-
tory; 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
On Visual Studio Generators, run before any other rules are exe-
cuted within the target. On other generators, run just before
PRE_LINK commands.
PRE_LINK
Run after sources have been compiled but before linking the bi-
nary or running the librarian or archiver tool of a static li-
brary. 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 us-
ing 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 11 2012 (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 expres-
sions.
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 af-
ter 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.
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]
[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 tar-
gets.
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 in-
terpreted 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 byprod-
ucts 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 re-
stricted set of generator expressions. Target-dependent expres-
sions are not permitted.
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 be-
fore 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.
DEPENDS
Reference files and outputs of custom commands created with
add_custom_command() command calls in the same directory (CMake-
Lists.txt file). They will be brought up to date when the tar-
get 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_DIRECTO-
RIES>,;-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.
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 pos-
sible. 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 direc-
tory.
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.
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 cur-
rent 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 defini-
tions.
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 defi-
nitions to specific scopes and configurations.
See 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 cre-
ated 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 the DEPENDS option of add_custom_target() and add_custom_command()
commands for adding file-level dependencies in custom rules. See 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 con-
ventions of the native platform (such as <name>.exe or just <name>).
New in version 3.1: Source arguments to add_executable may use "genera-
tor 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 direc-
tory 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 tar-
get 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-pro-
cessed, 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 di-
rectory 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 exe-
cutable are specified by setting properties whose names begin in IM-
PORTED_. The most important such property is IMPORTED_LOCATION (and
its per-configuration version IMPORTED_LOCATION_<CONFIG>) which speci-
fies the location of the main executable file on disk. See documenta-
tion 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 <tar-
get> in subsequent commands. The <name> does not appear in the gener-
ated 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 subdi-
rectories. 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, executa-
bles 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.
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 logi-
cal target name and must be globally unique within a project. The ac-
tual 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 us-
ing 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 in-
voked. See documentation of the ARCHIVE_OUTPUT_DIRECTORY,
LIBRARY_OUTPUT_DIRECTORY, and RUNTIME_OUTPUT_DIRECTORY target proper-
ties 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-pro-
cessed, 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 refer-
ence the objects using an expression of the form $<TARGET_OBJECTS:ob-
jlib> as a source, where objlib is the object library name. For exam-
ple:
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 con-
tain 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. How-
ever, it may have properties set on it and it may be installed and ex-
ported. Typically, INTERFACE_* properties are populated on an inter-
face 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 buildsys-
tem.
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 prop-
erty 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 com-
mands 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 re-
quirements 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 gener-
ated 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(). De-
tails 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 IM-
PORTED_LOCATION is the location of the .dll runtime library
(and is optional, but needed by the TARGET_RUNTIME_DLLS gener-
ator expression).
Additional usage requirements may be specified in INTERFACE_*
properties.
An UNKNOWN library type is typically only used in the implemen-
tation of Find Modules. It allows the path to an imported li-
brary (often found using the find_library() command) to be used
without having to know what type of library it is. This is es-
pecially 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 <tar-
get> in subsequent commands. The <name> does not appear in the gener-
ated 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 regu-
lar if(TARGET) subcommand. The <name> may not be used to modify prop-
erties 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.
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 com-
mands 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 tar-
gets, since they do not use a linker. To add archiver or MSVC li-
brarian 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 con-
trolled 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 de-
vice link). Options wrapped with $<DEVICE_LINK:...> generator expres-
sion 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 accumulat-
ing 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 us-
ing 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 sepa-
rator. 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 expres-
sion.
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.
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 direc-
tory 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 CMake-
Lists.txt file in the specified source directory will be processed im-
mediately by CMake before processing in the current input file contin-
ues beyond this command.
If the EXCLUDE_FROM_ALL argument is provided then targets in the subdi-
rectory 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 VS 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.
If the SYSTEM argument is provided, the SYSTEM directory property of
the subdirectory will be set to true. This property is used to ini-
tialize the SYSTEM property of each target created in that subdirec-
tory. The include directories of targets with SYSTEM set to true will
be treated as SYSTEM when compiling consumers.
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 charac-
ters, expressed as a Quoted Argument or Bracket Argument if necessary.
See policy CMP0110. The options are:
COMMAND
Specify the test command-line. If <command> specifies an exe-
cutable target (created by add_executable()) it will automati-
cally 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 WORKING_DIRECTORY test property to specify the working
directory in which to execute the test. If not specified the
test will be run with the current working directory set to the
build directory corresponding to the current source directory.
The working directory may be specified using generator expres-
sions.
COMMAND_EXPAND_LISTS
New in version 3.16.
Lists in COMMAND arguments will be expanded, including those
created with generator expressions.
The given test command is expected to exit with code 0 to pass and
non-zero to fail, or vice-versa if the WILL_FAIL test property is set.
Any output written to stdout or stderr will be captured by ctest(1) but
does not affect the pass/fail status unless the
PASS_REGULAR_EXPRESSION, FAIL_REGULAR_EXPRESSION or
SKIP_REGULAR_EXPRESSION test property is used.
New in version 3.16: Added SKIP_REGULAR_EXPRESSION property.
Tests added with the add_test(NAME) signature support using generator
expressions in test properties set by set_property(TEST) or
set_tests_properties().
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 pro-
duced by target myexe.
NOTE:
CMake will generate tests only if the enable_testing() command has
been invoked. The CTest module invokes the command automatically
unless the BUILD_TESTING option is turned OFF.
----
This command also supports a simpler, but less flexible, signature:
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 sup-
port 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 in-
tended 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 list-
ing 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 di-
rectory 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 in-
tended 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 CON-
FIGURATION, 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 underly-
ing 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 genera-
tor. Their implementation of the PROJECT_NAME option had no useful
effects, so CMake now warns on use of the option.
create_test_sourcelist
Create a test driver and source list for building test programs.
create_test_sourcelist(sourceListName driverName
test1 test2 test3
EXTRA_INCLUDE include.h
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 ar-
guments consist of a list of test source files, can be semicolon sepa-
rated. 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 a pointer to ac and av. 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 be-
fore 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 consid-
ered 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, includ-
ing 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 inher-
iting behavior when setting properties, so using APPEND or AP-
PEND_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 as-
sociated 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 op-
tional.
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.
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. Example languages are CXX, C,
CUDA, OBJC, OBJCXX, Fortran, HIP, ISPC, and ASM.
New in version 3.8: Added CUDA 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.
If enabling ASM, enable it last so that CMake can check whether compil-
ers 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 in-
directly 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 ex-
pects to find a test file in the build directory root.
This command is automatically invoked when the CTest module is in-
cluded, 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 executa-
bles 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 con-
sumers using CMake versions older than 2.8.12.
CXX_MODULES_DIRECTORY <directory>
NOTE:
Experimental. Gated by CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API
Export C++ module properties to files under the given directory.
Each file will be named according to the target's export name (with-
out any namespace). These files will automatically be included from
the export file.
This signature requires all targets to be listed explicitly. If a li-
brary 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 ar-
chitectures 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 us-
age requirements of other targets that link to the object libraries
in their implementation.
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 tar-
gets. 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 ex-
plicitly listed. Instead, it exports the targets associated with the
installation export <export-name>. Target installations may be associ-
ated 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 depen-
dent 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 reg-
istry.
Changed in version 3.1: If the CMAKE_EXPORT_NO_PACKAGE_REGISTRY vari-
able 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 reg-
istry 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 result-
ingLibraryName_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 source property is not
found, the behavior depends on whether it has been defined to be an IN-
HERITED property or not (see define_property()). Non-inherited proper-
ties will set variable to NOTFOUND, whereas inherited properties will
search the relevant parent scope as described for the define_property()
command and if still unable to find the property, variable will be set
to an empty string.
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, ei-
ther 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.
See also the more general get_property() command.
NOTE:
The GENERATED source file property may be globally visible. See its
documentation for details.
get_target_property
Get a property from a target.
get_target_property(<VAR> target property)
Get a property from a target. The value of the property is stored in
the variable <VAR>. If the target property is not found, the behavior
depends on whether it has been defined to be an INHERITED property or
not (see define_property()). Non-inherited properties will set <VAR>
to <VAR>-NOTFOUND, whereas inherited properties will search the rele-
vant parent scope as described for the define_property() command and if
still unable to find the property, <VAR> will be set to an empty
string.
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 the more general get_property() command.
See 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 VAR)
Get a property from the test. The value of the property is stored in
the variable VAR. If the test property is not found, the behavior de-
pends on whether it has been defined to be an INHERITED property or not
(see define_property()). Non-inherited properties will set VAR to
"NOTFOUND", whereas inherited properties will search the relevant par-
ent scope as described for the define_property() command and if still
unable to find the property, VAR will be set to an empty string.
For a list of standard properties you can type cmake --help-prop-
erty-list.
See also 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 in-
clude 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 ex-
plicitly, you can select between appending and prepending, independent
of the default.
If the SYSTEM option is given, the compiler will be told the directo-
ries are meant as system include directories on some platforms. Sig-
nalling this setting might achieve effects such as the compiler skip-
ping 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 di-
rectories to individual targets and optionally propagate/export them
to dependents.
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 [pro-
jectname]. 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 spec-
ify 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 match-
ing 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
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 genera-
tors, it is preferable to use relative paths throughout. In
particular, there is no need to make paths absolute by prepend-
ing CMAKE_INSTALL_PREFIX; this prefix is used by default if the
DESTINATION is a relative path.
PERMISSIONS
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 plat-
forms are ignored on those platforms.
CONFIGURATIONS
Specify a list of build configurations for which the install
rule applies (Debug, Release, etc.). Note that the values speci-
fied for this option only apply to options listed AFTER the CON-
FIGURATIONS option. For example, to set separate install paths
for the Debug and Release configurations, do the following:
install(TARGETS target
CONFIGURATIONS Debug
RUNTIME DESTINATION Debug/bin)
install(TARGETS target
CONFIGURATIONS Release
RUNTIME DESTINATION Release/bin)
Note that CONFIGURATIONS appears BEFORE RUNTIME DESTINATION.
COMPONENT
Specify an installation component name with which the install
rule is associated, such as Runtime or Development. During com-
ponent-specific installation only install rules associated with
the given component name will be executed. During a full in-
stallation all components are installed unless marked with EX-
CLUDE_FROM_ALL. If COMPONENT is not provided a default compo-
nent "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 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.
Installing Targets
install(TARGETS targets... [EXPORT <export-name>]
[RUNTIME_DEPENDENCIES args...|RUNTIME_DEPENDENCY_SET <set-name>]
[[ARCHIVE|LIBRARY|RUNTIME|OBJECTS|FRAMEWORK|BUNDLE|
PRIVATE_HEADER|PUBLIC_HEADER|RESOURCE|FILE_SET <set-name>|CXX_MODULES_BMI]
[DESTINATION <dir>]
[PERMISSIONS permissions...]
[CONFIGURATIONS [Debug|Release|...]]
[COMPONENT <component>]
[NAMELINK_COMPONENT <component>]
[OPTIONAL] [EXCLUDE_FROM_ALL]
[NAMELINK_ONLY|NAMELINK_SKIP]
] [...]
[INCLUDES DESTINATION [<dir> ...]]
)
The TARGETS form specifies rules for installing targets from a project.
There are several kinds of target Output Artifacts that may be in-
stalled:
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 li-
braries that go to RUNTIME);
• On AIX, the linker import file created for executables with
ENABLE_EXPORTS enabled.
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 prop-
erty 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 associ-
ated 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>
New in version 3.23.
File sets are defined by the target_sources(FILE_SET) command.
If the file set <set> exists and is PUBLIC or INTERFACE, any
files in the set are installed under the destination (see be-
low). 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 des-
tination.
CXX_MODULES_BMI
NOTE:
Experimental. Gated by CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API
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 DESTI-
NATION may be used to suppress installing these files (for use in
generic code).
For each of these arguments given, the arguments following them only
apply to the target or file type specified in the argument. If none is
given, the installation properties apply to all target types.
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 tar-
gets 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 destina-
tion, and the other component is not installed. If both RUNTIME and AR-
CHIVE destinations are specified, then both components are installed to
their respective destinations.
The following table shows the target types with their associated vari-
ables and built-in defaults that apply when no destination is given:
┌────────────────────┬─────────────────────┬──────────────────┐
│Target Type │ GNUInstallDirs │ Built-In Default │
│ │ Variable │ │
├────────────────────┼─────────────────────┼──────────────────┤
│RUNTIME │ ${CMAKE_IN- │ bin │
│ │ STALL_BINDIR} │ │
├────────────────────┼─────────────────────┼──────────────────┤
│LIBRARY │ ${CMAKE_IN- │ lib │
│ │ STALL_LIBDIR} │ │
└────────────────────┴─────────────────────┴──────────────────┘
│ARCHIVE │ ${CMAKE_IN- │ lib │
│ │ STALL_LIBDIR} │ │
├────────────────────┼─────────────────────┼──────────────────┤
│PRIVATE_HEADER │ ${CMAKE_INSTALL_IN- │ include │
│ │ CLUDEDIR} │ │
├────────────────────┼─────────────────────┼──────────────────┤
│PUBLIC_HEADER │ ${CMAKE_INSTALL_IN- │ include │
│ │ CLUDEDIR} │ │
├────────────────────┼─────────────────────┼──────────────────┤
│FILE_SET (type │ ${CMAKE_INSTALL_IN- │ include │
│HEADERS) │ CLUDEDIR} │ │
└────────────────────┴─────────────────────┴──────────────────┘
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 exam-
ple below).
To make packages compliant with distribution filesystem layout poli-
cies, if projects must specify a DESTINATION, it is recommended that
they use a path that begins with the appropriate GNUInstallDirs vari-
able. This allows package maintainers to control the install destina-
tion by setting the appropriate cache variables. The following example
shows a static library being installed to the default destination pro-
vided 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 li-
brary when given -l<name>. The NAMELINK_COMPONENT option is sim-
ilar 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.
Consider the following example:
install(TARGETS mylib
LIBRARY
COMPONENT Libraries
NAMELINK_COMPONENT Development
PUBLIC_HEADER
COMPONENT Development
)
In this scenario, if you choose to install only the Development
component, both the headers and namelink will be installed with-
out the library. (If you don't also install the Libraries compo-
nent, the namelink will be a dangling symlink, and projects that
link to the library will have build errors.) If you install only
the Libraries component, only the library will be installed,
without the headers and namelink.
This option is typically used for package managers that have
separate runtime and development packages. For example, on De-
bian systems, the library is expected to be in the runtime pack-
age, and the headers and namelink are expected to be in the de-
velopment 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 ver-
sioned, the NAMELINK_ONLY option installs nothing. It is an er-
ror to use this parameter outside of a LIBRARY block.
When NAMELINK_ONLY is given, either NAMELINK_COMPONENT or COMPO-
NENT 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 LI-
BRARY block.
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 argu-
ments. All PUBLIC or INTERFACE file sets associated with a tar-
get 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
New in version 3.21.
This option causes all runtime dependencies of installed exe-
cutable, 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
New in version 3.21.
This option causes all runtime dependencies of installed exe-
cutable, shared library, and module targets to be installed
along with the targets themselves. The RUNTIME, LIBRARY, FRAME-
WORK, and generic arguments are used to determine the properties
(DESTINATION, COMPONENT, etc.) of the installation of these de-
pendencies.
RUNTIME_DEPENDENCIES is semantically equivalent to the following
pair of calls:
install(TARGETS ... RUNTIME_DEPENDENCY_SET <set-name>)
install(RUNTIME_DEPENDENCY_SET <set-name> args...)
where <set-name> will be a randomly generated set name. The
args... 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.
One or more groups of properties may be specified in a single call to
the TARGETS form of this command. A target may be installed more than
once to different locations. Consider hypothetical targets myExe,
mySharedLib, and myStaticLib. The code:
install(TARGETS myExe mySharedLib myStaticLib
RUNTIME DESTINATION bin
LIBRARY DESTINATION lib
ARCHIVE DESTINATION lib/static)
install(TARGETS mySharedLib DESTINATION /some/full/path)
will install myExe to <prefix>/bin and myStaticLib to <pre-
fix>/lib/static. On non-DLL platforms mySharedLib will be installed to
<prefix>/lib and /some/full/path. On DLL platforms the mySharedLib DLL
will be installed to <prefix>/bin and /some/full/path and its import
library will be installed to <prefix>/lib/static and /some/full/path.
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 suffi-
cient 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 argu-
ment 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 in-
stall rules are run.
Installing Imported Runtime Artifacts
New in version 3.21.
install(IMPORTED_RUNTIME_ARTIFACTS targets...
[RUNTIME_DEPENDENCY_SET <set-name>]
[[LIBRARY|RUNTIME|FRAMEWORK|BUNDLE]
[DESTINATION <dir>]
[PERMISSIONS permissions...]
[CONFIGURATIONS [Debug|Release|...]]
[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 installa-
tion. The LIBRARY, RUNTIME, FRAMEWORK, and BUNDLE arguments have the
same semantics that they do in the TARGETS mode. Only the runtime arti-
facts 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 executa-
bles, 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.
Installing Files
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|PROGRAMS> files...
TYPE <type> | DESTINATION <dir>
[PERMISSIONS permissions...]
[CONFIGURATIONS [Debug|Release|...]]
[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 de-
fault 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 ex-
pressions" with the syntax $<...>. See the
cmake-generator-expressions(7) manual for available expressions. How-
ever, 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 correspond-
ing 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 │ Built-In Default │
│ │ Variable │ │
├──────────────┼─────────────────────┼─────────────────────┤
│BIN │ ${CMAKE_IN- │ bin │
│ │ STALL_BINDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│SBIN │ ${CMAKE_IN- │ sbin │
│ │ STALL_SBINDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│LIB │ ${CMAKE_IN- │ lib │
│ │ STALL_LIBDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│INCLUDE │ ${CMAKE_INSTALL_IN- │ include │
│ │ CLUDEDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│SYSCONF │ ${CMAKE_IN- │ etc │
│ │ STALL_SYSCONFDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│SHAREDSTATE │ ${CMAKE_IN- │ com │
│ │ STALL_SHARESTATE- │ │
│ │ DIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│LOCALSTATE │ ${CMAKE_INSTALL_LO- │ var │
│ │ CALSTATEDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│RUNSTATE │ ${CMAKE_IN- │ <LOCALSTATE │
│ │ STALL_RUNSTATEDIR} │ dir>/run │
├──────────────┼─────────────────────┼─────────────────────┤
│DATA │ ${CMAKE_IN- │ <DATAROOT dir> │
│ │ STALL_DATADIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│INFO │ ${CMAKE_INSTALL_IN- │ <DATAROOT dir>/info │
│ │ FODIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│LOCALE │ ${CMAKE_INSTALL_LO- │ <DATAROOT dir>/lo- │
│ │ CALEDIR} │ cale │
├──────────────┼─────────────────────┼─────────────────────┤
│MAN │ ${CMAKE_IN- │ <DATAROOT dir>/man │
│ │ STALL_MANDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│DOC │ ${CMAKE_IN- │ <DATAROOT dir>/doc │
│ │ STALL_DOCDIR} │ │
└──────────────┴─────────────────────┴─────────────────────┘
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 direc-
tory 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 poli-
cies, if projects must specify a DESTINATION, it is recommended that
they use a path that begins with the appropriate GNUInstallDirs vari-
able. This allows package maintainers to control the install destina-
tion 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 argu-
ment 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.
Installing Directories
NOTE:
To install a directory sub-tree of headers, consider using file sets
defined by target_sources(FILE_SET) instead. File sets not only pre-
serve directory structure, they also associate headers with a target
and install as part of the target.
install(DIRECTORY dirs...
TYPE <type> | DESTINATION <dir>
[FILE_PERMISSIONS permissions...]
[DIRECTORY_PERMISSIONS permissions...]
[USE_SOURCE_PERMISSIONS] [OPTIONAL] [MESSAGE_NEVER]
[CONFIGURATIONS [Debug|Release|...]]
[COMPONENT <component>] [EXCLUDE_FROM_ALL]
[FILES_MATCHING]
[[PATTERN <pattern> | REGEX <regex>]
[EXCLUDE] [PERMISSIONS permissions...]] [...])
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 di-
rectory 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_PER-
MISSIONS 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 us-
ing 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 cer-
tain options (see below) to a subset of the files and directories en-
countered. 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 op-
tion may be given before the first match option to disable installation
of files (but not directories) not matched by any expression. For ex-
ample, 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 un-
der 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 permis-
sions, the scripts will be given specific permissions, and any CVS di-
rectories 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 automati-
cally by taking the corresponding variable from GNUInstallDirs, or by
using a built-in default if that variable is not defined. See the ta-
ble below for the supported file types and their corresponding vari-
ables and built-in defaults. Projects can provide a DESTINATION argu-
ment instead of a file type if they wish to explicitly define the in-
stall destination.
┌──────────────┬─────────────────────┬─────────────────────┐
│TYPE Argument │ GNUInstallDirs │ Built-In Default │
│ │ Variable │ │
├──────────────┼─────────────────────┼─────────────────────┤
│BIN │ ${CMAKE_IN- │ bin │
│ │ STALL_BINDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│SBIN │ ${CMAKE_IN- │ sbin │
│ │ STALL_SBINDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│LIB │ ${CMAKE_IN- │ lib │
│ │ STALL_LIBDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│INCLUDE │ ${CMAKE_INSTALL_IN- │ include │
│ │ CLUDEDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│SYSCONF │ ${CMAKE_IN- │ etc │
│ │ STALL_SYSCONFDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│SHAREDSTATE │ ${CMAKE_IN- │ com │
│ │ STALL_SHARESTATE- │ │
│ │ DIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│LOCALSTATE │ ${CMAKE_INSTALL_LO- │ var │
│ │ CALSTATEDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│RUNSTATE │ ${CMAKE_IN- │ <LOCALSTATE │
│ │ STALL_RUNSTATEDIR} │ dir>/run │
├──────────────┼─────────────────────┼─────────────────────┤
│DATA │ ${CMAKE_IN- │ <DATAROOT dir> │
│ │ STALL_DATADIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│INFO │ ${CMAKE_INSTALL_IN- │ <DATAROOT dir>/info │
│ │ FODIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│LOCALE │ ${CMAKE_INSTALL_LO- │ <DATAROOT dir>/lo- │
│ │ CALEDIR} │ cale │
├──────────────┼─────────────────────┼─────────────────────┤
│MAN │ ${CMAKE_IN- │ <DATAROOT dir>/man │
│ │ STALL_MANDIR} │ │
├──────────────┼─────────────────────┼─────────────────────┤
│DOC │ ${CMAKE_IN- │ <DATAROOT dir>/doc │
│ │ STALL_DOCDIR} │ │
└──────────────┴─────────────────────┴─────────────────────┘
Note that some of the types' built-in defaults use the DATAROOT direc-
tory 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 poli-
cies, if projects must specify a DESTINATION, it is recommended that
they use a path that begins with the appropriate GNUInstallDirs vari-
able. This allows package maintainers to control the install destina-
tion by setting the appropriate cache variables.
New in version 3.4: An install destination given as a DESTINATION argu-
ment 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.
Custom Installation Logic
install([[SCRIPT <file>] [CODE <code>]]
[ALL_COMPONENTS | COMPONENT <component>]
[EXCLUDE_FROM_ALL] [...])
The SCRIPT form will invoke the given CMake script files during instal-
lation. If the script file name is a relative path it will be inter-
preted with respect to the current source directory. The CODE form
will invoke the given CMake code during installation. Code is speci-
fied 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 cus-
tom 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.
Installing Exports
install(EXPORT <export-name> DESTINATION <dir>
[NAMESPACE <namespace>] [FILE <name>.cmake]
[PERMISSIONS permissions...]
[CONFIGURATIONS [Debug|Release|...]
[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. The EXPORT_LINK_INTERFACE_LI-
BRARIES keyword, if present, causes the contents of the properties
matching (IMPORTED_)?LINK_INTERFACE_LIBRARIES(_<CONFIG>)? to be ex-
ported, 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 glob-
bing. 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 de-
pends 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 compo-
nent 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 com-
ponent 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_AN-
DROID_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 depen-
dencies, include flags and defines required to use the libraries.
CXX_MODULES_DIRECTORY
NOTE:
Experimental. Gated by CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API
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 tar-
gets. 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 <pre-
fix>/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.
Installing Runtime Dependencies
New in version 3.21.
install(RUNTIME_DEPENDENCY_SET <set-name>
[[LIBRARY|RUNTIME|FRAMEWORK]
[DESTINATION <dir>]
[PERMISSIONS permissions...]
[CONFIGURATIONS [Debug|Release|...]]
[COMPONENT <component>]
[NAMELINK_COMPONENT <component>]
[OPTIONAL] [EXCLUDE_FROM_ALL]
] [...]
[PRE_INCLUDE_REGEXES regexes...]
[PRE_EXCLUDE_REGEXES regexes...]
[POST_INCLUDE_REGEXES regexes...]
[POST_EXCLUDE_REGEXES regexes...]
[POST_INCLUDE_FILES files...]
[POST_EXCLUDE_FILES files...]
[DIRECTORIES directories...]
)
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 in-
stalled 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 them-
selves 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 ex-
ecutables is a MACOSX_BUNDLE, that executable is passed as the BUN-
DLE_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 <directories>
• PRE_INCLUDE_REGEXES <regexes>
• PRE_EXCLUDE_REGEXES <regexes>
• POST_INCLUDE_REGEXES <regexes>
• POST_EXCLUDE_REGEXES <regexes>
• POST_INCLUDE_FILES <files>
• POST_EXCLUDE_FILES <files>
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 tar-
get 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_in-
stall.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. Rela-
tive 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 rel-
ative 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 ar-
chitecture 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.
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 direc-
tory-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_IN-
TERNALS can be used to provide a list of internal entries to be in-
cluded. 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 correspond-
ing 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 com-
ponents, 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 CMake-
Lists.txt, then the description is also stored in the variable
CMAKE_PROJECT_DESCRIPTION.
New in version 3.12: Added the <PROJECT-NAME>_DESCRIPTION vari-
able.
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 CMake-
Lists.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 include C, CXX (i.e. C++), CUDA,
OBJC (i.e. Objective-C), OBJCXX, Fortran, HIP, ISPC, and ASM.
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.
New in version 3.8: Added CUDA support.
New in version 3.16: Added OBJC and OBJCXX support.
New in version 3.18: Added ISPC support.
If enabling ASM, list it last so that CMake can check whether
compilers for other languages like C work for assembly too.
The variables set through the VERSION, DESCRIPTION and HOMEPAGE_URL op-
tions 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() com-
mand. 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. Lan-
guage-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 en-
abling 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 CMake-
Lists.txt, but after calling cmake_minimum_required(). It is impor-
tant to establish version and policy settings before invoking other
commands whose behavior they may affect. 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 visi-
ble to targets added in the same directory (CMakeLists.txt). Visibil-
ity can be set in other directory scopes using one or both of the fol-
lowing options:
DIRECTORY <dirs>...
The source file properties will be set in each of the <dirs> di-
rectories' 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 direc-
tory. 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.
See Properties on Source Files for the list of properties known to
CMake.
NOTE:
The GENERATED source file property may be globally visible. See its
documentation for details.
set_target_properties
Targets can have properties that affect how they are built.
set_target_properties(target1 target2 ...
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.
See also the set_property(TARGET) command.
See Properties on Targets for the list of properties known to CMake.
set_tests_properties
Set a property of the tests.
set_tests_properties(test1 [test2...] 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.
See also the set_property(TEST) command.
See 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 cur-
rent 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 explic-
itly 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 sub-
groups.
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 popu-
late the COMPILE_DEFINITIONS property of <target>. PUBLIC and INTERFACE
items will populate the INTERFACE_COMPILE_DEFINITIONS property of <tar-
get>. 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. Intel-
liSense).
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 re-
quires 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.
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.
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.
Arguments
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 popu-
late 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 accumulat-
ing 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 us-
ing 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 pre-
processor 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.
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 popu-
late the INCLUDE_DIRECTORIES property of <target>. PUBLIC and INTERFACE
items will populate the INTERFACE_INCLUDE_DIRECTORIES property of <tar-
get>. 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 directo-
ries 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 unmodi-
fied.
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 sepa-
rate 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 in-
stalled 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 speci-
fying usage requirements while creating packages for redistribution.
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 pop-
ulate 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 ar-
chitecture 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).
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 com-
pilation 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 <tar-
get> 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 de-
pendency 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 3.8: 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 dependen-
cies, 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, depend-
ing 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 an-
other <item>. The item following such a keyword will be used only
for the corresponding build configuration. The debug keyword corre-
sponds 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 inter-
preted 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 fol-
lowing 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 set-
ting 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 li-
braries 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 li-
braries are also appended to the LINK_INTERFACE_LIBRARIES_DEBUG prop-
erty (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 op-
timized.
Linking Object Libraries
New in version 3.12.
Object Libraries may be used as the <target> (first) argument of tar-
get_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 re-
quirements, 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 Li-
braries, 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 rela-
tive 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 fol-
lowed 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 exam-
ple, 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 ob-
ject 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 tran-
sitive 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, in-
cluding 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 com-
ponent. 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 tar-
get_link_libraries call. However, if two archives are really so inter-
dependent they should probably be combined into a single archive, per-
haps 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 speci-
fying usage requirements while creating packages for redistribution.
target_link_options
New in version 3.13.
Add options to the link step for an executable, shared library or mod-
ule 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 com-
mands 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 tar-
gets, since they do not use a linker. To add archiver or MSVC li-
brarian 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 popu-
late 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 con-
trolled 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 de-
vice link). Options wrapped with $<DEVICE_LINK:...> generator expres-
sion 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 accumulat-
ing 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 us-
ing 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 sepa-
rator. 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 expres-
sion.
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.
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 par-
tially processed version of some header files, and then using that ver-
sion 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 popu-
late the PRECOMPILE_HEADERS property of <target>. PUBLIC and INTERFACE
items will populate the INTERFACE_PRECOMPILE_HEADERS property of <tar-
get> (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 head-
ers 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 require-
ments). 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 li-
brary 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>
)
Arguments to target_precompile_headers() may use "generator expres-
sions" with the syntax $<...>. See the cmake-generator-expressions(7)
manual for available expressions. The $<COMPILE_LANGUAGE:...> genera-
tor expression is particularly useful for specifying a language-spe-
cific 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 spec-
ify that one target re-uses a precompiled header file artifact from an-
other 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 RE-
USE_FROM form is used.
NOTE:
The REUSE_FROM form requires the same set of compiler options, com-
piler 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_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 direc-
tories, and files within those directories. The acceptable types in-
clude:
HEADERS
Sources intended to be used via a language's #include mechanism.
CXX_MODULES
NOTE:
Experimental. Gated by CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API
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.
CXX_MODULE_HEADER_UNITS
NOTE:
Experimental. Gated by CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API
C++ header sources which may be imported by other C++ source code.
This file set type may not have an INTERFACE scope except on IM-
PORTED 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 IN-
TERFACE 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 let-
ter 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 under-
score.
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 any-
thing 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 directo-
ries 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>
For file sets of type CXX_MODULE_HEADER_UNITS:
• CXX_MODULE_HEADER_UNIT_SETS
• INTERFACE_CXX_MODULE_HEADER_UNIT_SETS
• CXX_MODULE_HEADER_UNIT_SET
• CXX_MODULE_HEADER_UNIT_SET_<NAME>
• CXX_MODULE_HEADER_UNIT_DIRS
• CXX_MODULE_HEADER_UNIT_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 or CXX_MODULE_HEADER_UNITS, 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 or CXX_MODULE_HEADER_UNITS, 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.
try_compile
Try building some code.
Try Compiling Whole Projects
try_compile(<resultVar> PROJECT <projectName>
SOURCE_DIR <srcdir>
[BINARY_DIR <bindir>]
[TARGET <targetName>]
[NO_CACHE]
[CMAKE_FLAGS <flags>...]
[OUTPUT_VARIABLE <var>])
New in version 3.25.
Try building a project. The success or failure of the try_compile,
i.e. TRUE or FALSE respectively, is returned in <resultVar>.
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.
This command also supports an alternate signature which was present in
older versions of CMake:
try_compile(<resultVar> <bindir> <srcdir>
<projectName> [<targetName>]
[NO_CACHE]
[CMAKE_FLAGS <flags>...]
[OUTPUT_VARIABLE <var>])
Try Compiling Source Files
try_compile(<resultVar>
<SOURCES <srcfile...> |
SOURCE_FROM_CONTENT <name> <content> |
SOURCE_FROM_VAR <name> <var> |
SOURCE_FROM_FILE <name> <path> >...
[NO_CACHE]
[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). The success or failure of the try_compile, i.e. TRUE or
FALSE respectively, is returned in <resultVar>.
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 li-
brary 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 un-
specified 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 ex-
ecution.
This command also supports an alternate signature which was present in
older versions of CMake:
try_compile(<resultVar> <bindir> <srcfile|SOURCES srcfile...>
[NO_CACHE]
[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.
The options 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 <file-
Name>.
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 vari-
able.
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.
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 direc-
tory. This can be used to bypass the need to separately write a
source file when the contents of the file are dynamically speci-
fied. The specified <name> is not allowed to contain path compo-
nents.
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 direc-
tory, 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 opera-
tion 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.
<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 gener-
ated 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 ob-
tain 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 the CMAKE_TRY_COMPILE_CONFIGURATION variable to choose a build con-
figuration.
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 vari-
able 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 propa-
gated into the test project.
New in version 3.24: The CMAKE_TRY_COMPILE_NO_PLATFORM_VARIABLES vari-
able 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 informa-
tion format.
try_run
Try compiling and then running some code.
Try Compiling and Running Source Files
try_run(<runResultVar> <compileResultVar>
<SOURCES <srcfile...> |
SOURCE_FROM_CONTENT <name> <content> |
SOURCE_FROM_VAR <name> <var> |
SOURCE_FROM_FILE <name> <path> >...
[NO_CACHE]
[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>]
[OUTPUT_VARIABLE <var>]
[WORKING_DIRECTORY <var>]
[ARGS <args>...]
)
New in version 3.25.
Try compiling a <srcfile>. Returns TRUE or FALSE for success or fail-
ure in <compileResultVar>. If the compile succeeded, runs the exe-
cutable and returns its exit code in <runResultVar>. If the executable
was built, but failed to run, then <runResultVar> will be set to
FAILED_TO_RUN. See the try_compile() command for documentation of op-
tions 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.
This command also supports an alternate signature which was present in
older versions of CMake:
try_run(<runResultVar> <compileResultVar>
<bindir> <srcfile|SOURCES srcfile...>
[NO_CACHE]
[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>]
[OUTPUT_VARIABLE <var>]
[WORKING_DIRECTORY <var>]
[ARGS <args>...]
)
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 vari-
able.
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_DIREC-
TORY 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 the CMAKE_TRY_COMPILE_CONFIGURATION variable to choose a build con-
figuration.
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-com-
piling mode. If that is the case, it will still try to compile the ex-
ecutable, 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 pro-
duced 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 plat-
form.
<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_OUT-
PUT_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_STD-
OUT_VARIABLE, RUN_OUTPUT_STDERR_VARIABLE, RUN_OUTPUT_VARIABLE or OUT-
PUT_VARIABLE options only if really required. Using them will require
that when cross-compiling, the cache variables will have to be set man-
ually to the output of the executable. You can also "guard" the calls
to try_run with an if() block checking the CMAKE_CROSSCOMPILING vari-
able 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 auto-
matically 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 se-
mantics 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. Other-
wise 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 vari-
able 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 de-
fault 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 vari-
able.
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 na-
tive 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 underly-
ing 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 sub-
mission 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 with-
out 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 op-
tion.
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 ac-
cidental 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 Mem-
Check.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 af-
ter the binary directory is initialized.
The parameters are as follows:
<model>
Set the dashboard model. Must be one of Experimental, Continu-
ous, 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 warn-
ing 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 vari-
able) 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 reposi-
tory.
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 sub-
mission 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 dur-
ing 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 head-
ers.
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 submis-
sion 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 se-
mantics 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 num-
bers.
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 particu-
lar fixture, that fixture's setup and cleanup tests would nor-
mally be added to the test set automatically. This option pre-
vents adding setup or cleanup tests for fixtures matching the
<regex>. Note that all other fixture behavior is retained, in-
cluding 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 ex-
cluded.
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 or-
der 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 use-
ful 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 ma-
chines.
SCHEDULE_RANDOM <ON|OFF>
Launch tests in a random order. This may be useful for detect-
ing 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 run-
ning.
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 re-
sulting 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 underly-
ing test command is not affected. Summary info detailing the
percentage of passing tests is also unaffected by the QUIET op-
tion.
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 corre-
sponding 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 re-
port to CDash.
When run as a Dashboard Client, CTest will include these custom mea-
surements 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 Va-
lidImage (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 in-
stead.
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 Up-
date.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_up-
date().
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
Deprecated since version 3.0: Use the execute_process() command in-
stead.
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 exe-
cutable 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 exe-
cutable path. An optional argument OUTPUT_VARIABLE specifies a vari-
able 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 in-
stallation 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 com-
mands that will set all the variables needed for library dependency in-
formation. This should be the last command in the top level CMake-
Lists.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 pro-
vided for compatibility with older CMake code. The FILES form is di-
rectly 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 typi-
cal extension is .h.
install_files(<dir> regexp)
Any files in the current source directory that match the regular ex-
pression 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 in-
stead.
This command has been superseded by the install() command. It is pro-
vided for compatibility with older CMake code. The FILES form is di-
rectly 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 pro-
vided 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 cmCOM-
MAND_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 success-
fully 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 in-
stead.
make_directory(directory)
Creates the specified directory. Full paths should be given. Any par-
ent 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 speci-
fied 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 pro-
vides 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 in-
stead 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 pro-
vides 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 Head-
ersDestNamesource list. The .cxx files will be added to the library
using the SourcesDestNamesource list.
Consider updating the project to use the AUTOUIC target property in-
stead for a more automated way of invoking the uic tool.
remove
Deprecated since version 3.0: Use the list(REMOVE_ITEM) command in-
stead.
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 ex-
panded.
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 paral-
lel builds correctly. This functionality is now automatic.
subdirs
Deprecated since version 3.0: Use the add_subdirectory() command in-
stead.
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() com-
mand 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 exam-
ples 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 head-
ers 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 as-
sumed 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 exe-
cutable which is executed later on. This doesn't work when cross com-
piling, 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_VARI-
ABLE 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 mes-
sages 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 in-
put files to CMake.
COPYRIGHT
2000-2022 Kitware, Inc. and Contributors
3.25.1 November 30, 2022 CMAKE-COMMANDS(7)
Generated by dwww version 1.15 on Tue Jun 25 20:40:20 CEST 2024.