Provided by: cmake-data_3.22.1-1ubuntu1.22.04.2_all 
NAME
cmake-commands - CMake Language Command Reference
SCRIPTING COMMANDS
These commands are always available.
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 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 filename has the following format: NNN-<name>.cmake, where NNN is three
digits used to apply collected scripts in a specific order.
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_<varname>
Variables collected by the user provided fallback script ought to be assigned to CMake variables
using this naming convention. Example, the ID variable from the manual becomes
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID.
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT
The fallback script ought to store names of all assigned
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_<varname> variables in this list.
Example:
# Try to detect some old distribution
# See also
# - http://linuxmafia.com/faq/Admin/release-files.html
#
if(NOT EXISTS "${CMAKE_SYSROOT}/etc/foobar-release")
return()
endif()
# Get the first string only
file(
STRINGS "${CMAKE_SYSROOT}/etc/foobar-release" CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT
LIMIT_COUNT 1
)
#
# Example:
#
# Foobar distribution release 1.2.3 (server)
#
if(CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT MATCHES "Foobar distribution release ([0-9\.]+) .*")
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_NAME Foobar)
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_PRETTY_NAME "${CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT}")
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID foobar)
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION ${CMAKE_MATCH_1})
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION_ID ${CMAKE_MATCH_1})
list(
APPEND CMAKE_GET_OS_RELEASE_FALLBACK_RESULT
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_NAME
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_PRETTY_NAME
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION_ID
)
endif()
unset(CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT)
FOOTNOTES
[1] One MiB (mebibyte) is equal to 1024x1024 bytes.
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>...])
Introduction
This command will call meta-operations on built-in CMake commands or those created via the macro() or
function() commands.
cmake_language does not introduce a new variable or policy scope.
Calling Commands
cmake_language(CALL <command> [<arg>...])
Calls the named <command> with the given arguments (if any). For example, the code:
set(message_command "message")
cmake_language(CALL ${message_command} STATUS "Hello World!")
is equivalent to
message(STATUS "Hello World!")
NOTE:
To ensure consistency of the code, the following commands are not allowed:
• if / elseif / else / endif
• while / endwhile
• foreach / endforeach
• function / endfunction
• macro / endmacro
Evaluating Code
cmake_language(EVAL CODE <code>...)
Evaluates the <code>... as CMake code.
For example, the code:
set(A TRUE)
set(B TRUE)
set(C TRUE)
set(condition "(A AND B) OR C")
cmake_language(EVAL CODE "
if (${condition})
message(STATUS TRUE)
else()
message(STATUS FALSE)
endif()"
)
is equivalent to
set(A TRUE)
set(B TRUE)
set(C TRUE)
set(condition "(A AND B) OR C")
file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/eval.cmake "
if (${condition})
message(STATUS TRUE)
else()
message(STATUS FALSE)
endif()"
)
include(${CMAKE_CURRENT_BINARY_DIR}/eval.cmake)
Deferring Calls
New in version 3.19.
cmake_language(DEFER <options>... CALL <command> [<arg>...])
Schedules a call to the named <command> with the given arguments (if any) to occur at a later time. By
default, deferred calls are executed as if written at the end of the current directory's CMakeLists.txt
file, except that they run even after a return() call. Variable references in arguments are evaluated at
the time the deferred call is executed.
The options are:
DIRECTORY <dir>
Schedule the call for the end of the given directory instead of the current directory. The <dir>
may reference either a source directory or its corresponding binary directory. Relative paths are
treated as relative to the current source directory.
The given directory must be known to CMake, being either the top-level directory or one added by
add_subdirectory(). Furthermore, the given directory must not yet be finished processing. This
means it can be the current directory or one of its ancestors.
ID <id>
Specify an identification for the deferred call. The <id> may not be empty and may not begin with
a capital letter A-Z. The <id> may begin with an underscore (_) only if it was generated
automatically by an earlier call that used ID_VAR to get the id.
ID_VAR <var>
Specify a variable in which to store the identification for the deferred call. If ID <id> is not
given, a new identification will be generated and the generated id will start with an underscore
(_).
The currently scheduled list of deferred calls may be retrieved:
cmake_language(DEFER [DIRECTORY <dir>] GET_CALL_IDS <var>)
This will store in <var> a semicolon-separated list of deferred call ids. The ids are for the directory
scope in which the calls have been deferred to (i.e. where they will be executed), which can be different
to the scope in which they were created. The DIRECTORY option can be used to specify the scope for which
to retrieve the call ids. If that option is not given, the call ids for the current directory scope will
be returned.
Details of a specific call may be retrieved from its id:
cmake_language(DEFER [DIRECTORY <dir>] GET_CALL <id> <var>)
This will store in <var> a semicolon-separated list in which the first element is the name of the command
to be called, and the remaining elements are its unevaluated arguments (any contained ; characters are
included literally and cannot be distinguished from multiple arguments). If multiple calls are scheduled
with the same id, this retrieves the first one. If no call is scheduled with the given id in the
specified DIRECTORY scope (or the current directory scope if no DIRECTORY option is given), this stores
an empty string in the variable.
Deferred calls may be canceled by their id:
cmake_language(DEFER [DIRECTORY <dir>] CANCEL_CALL <id>...)
This cancels all deferred calls matching any of the given ids in the specified DIRECTORY scope (or the
current directory scope if no DIRECTORY option is given). Unknown ids are silently ignored.
Deferred Call Examples
For example, the code:
cmake_language(DEFER CALL message "${deferred_message}")
cmake_language(DEFER ID_VAR id CALL message "Canceled Message")
cmake_language(DEFER CANCEL_CALL ${id})
message("Immediate Message")
set(deferred_message "Deferred Message")
prints:
Immediate Message
Deferred Message
The Cancelled Message is never printed because its command is canceled. The deferred_message variable
reference is not evaluated until the call site, so it can be set after the deferred call is scheduled.
In order to evaluate variable references immediately when scheduling a deferred call, wrap it using
cmake_language(EVAL). However, note that arguments will be re-evaluated in the deferred call, though
that can be avoided by using bracket arguments. For example:
set(deferred_message "Deferred Message 1")
set(re_evaluated [[${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
cmake_minimum_required
Require a minimum version of cmake.
cmake_minimum_required(VERSION <min>[...<policy_max>] [FATAL_ERROR])
New in version 3.12: The optional <policy_max> version.
Sets the minimum required version of cmake for a project. Also updates the policy settings as explained
below.
<min> and the optional <policy_max> are each CMake versions of the form major.minor[.patch[.tweak]], and
the ... is literal.
If the running version of CMake is lower than the <min> required version it will stop processing the
project and report an error. The optional <policy_max> version, if specified, must be at least the <min>
version and affects policy settings as described in Policy Settings. If the running version of CMake is
older than 3.12, the extra ... dots will be seen as version component separators, resulting in the
...<max> part being ignored and preserving the pre-3.12 behavior of basing policies on <min>.
This command will set the value of the CMAKE_MINIMUM_REQUIRED_VERSION variable to <min>.
The FATAL_ERROR option is accepted but ignored by CMake 2.6 and higher. It should be specified so CMake
versions 2.4 and lower fail with an error instead of just a warning.
NOTE:
Call the cmake_minimum_required() command at the beginning of the top-level CMakeLists.txt file even
before calling the project() command. It is important to establish version and policy settings before
invoking other commands whose behavior they may affect. See also policy CMP0000.
Calling cmake_minimum_required() inside a function() limits some effects to the function scope when
invoked. For example, the CMAKE_MINIMUM_REQUIRED_VERSION variable won't be set in the calling scope.
Functions do not introduce their own policy scope though, so policy settings of the caller will be
affected (see below). Due to this mix of things that do and do not affect the calling scope, calling
cmake_minimum_required() inside a function is generally discouraged.
Policy Settings
The cmake_minimum_required(VERSION) command implicitly invokes the cmake_policy(VERSION) command to
specify that the current project code is written for the given range of CMake versions. All policies
known to the running version of CMake and introduced in the <min> (or <max>, if specified) version or
earlier will be set to use NEW behavior. All policies introduced in later versions will be unset. This
effectively requests behavior preferred as of a given CMake version and tells newer CMake versions to
warn about their new policies.
When a <min> version higher than 2.4 is specified the command implicitly invokes
cmake_policy(VERSION <min>[...<max>])
which sets CMake policies based on the range of versions specified. When a <min> version 2.4 or lower is
given the command implicitly invokes
cmake_policy(VERSION 2.4[...<max>])
which enables compatibility features for CMake 2.4 and lower.
cmake_parse_arguments
Parse function or macro arguments.
cmake_parse_arguments(<prefix> <options> <one_value_keywords>
<multi_value_keywords> <args>...)
cmake_parse_arguments(PARSE_ARGV <N> <prefix> <options>
<one_value_keywords> <multi_value_keywords>)
New in version 3.5: This command is implemented natively. Previously, it has been defined in the module
CMakeParseArguments.
This command is for use in macros or functions. It processes the arguments given to that macro or
function, and defines a set of variables which hold the values of the respective options.
The first signature reads processes arguments passed in the <args>.... This may be used in either a
macro() or a function().
New in version 3.7: The PARSE_ARGV signature is only for use in a function() body. In this case the
arguments that are parsed come from the ARGV# variables of the calling function. The parsing starts with
the <N>-th argument, where <N> is an unsigned integer. This allows for the values to have special
characters like ; in them.
The <options> argument contains all options for the respective macro, i.e. keywords which can be used
when calling the macro without any value following, like e.g. the OPTIONAL keyword of the install()
command.
The <one_value_keywords> argument contains all keywords for this macro which are followed by one value,
like e.g. DESTINATION keyword of the install() command.
The <multi_value_keywords> argument contains all keywords for this macro which can be followed by more
than one value, like e.g. the TARGETS or FILES keywords of the install() command.
Changed in version 3.5: All keywords shall be unique. I.e. every keyword shall only be specified once in
either <options>, <one_value_keywords> or <multi_value_keywords>. A warning will be emitted if uniqueness
is violated.
When done, cmake_parse_arguments will consider for each of the keywords listed in <options>,
<one_value_keywords> and <multi_value_keywords> a variable composed of the given <prefix> followed by "_"
and the name of the respective keyword. These variables will then hold the respective value from the
argument list or be undefined if the associated option could not be found. For the <options> keywords,
these will always be defined, to TRUE or FALSE, whether the option is in the argument list or not.
All remaining arguments are collected in a variable <prefix>_UNPARSED_ARGUMENTS that will be undefined if
all arguments were recognized. This can be checked afterwards to see whether your macro was called with
unrecognized parameters.
New in version 3.15: <one_value_keywords> and <multi_value_keywords> that were given no values at all are
collected in a variable <prefix>_KEYWORDS_MISSING_VALUES that will be undefined if all keywords received
values. This can be checked to see if there were keywords without any values given.
Consider the following example macro, my_install(), which takes similar arguments to the real install()
command:
macro(my_install)
set(options OPTIONAL FAST)
set(oneValueArgs DESTINATION RENAME)
set(multiValueArgs TARGETS CONFIGURATIONS)
cmake_parse_arguments(MY_INSTALL "${options}" "${oneValueArgs}"
"${multiValueArgs}" ${ARGN} )
# ...
Assume my_install() has been called like this:
my_install(TARGETS foo bar DESTINATION bin OPTIONAL blub CONFIGURATIONS)
After the cmake_parse_arguments call the macro will have set or undefined the following variables:
MY_INSTALL_OPTIONAL = TRUE
MY_INSTALL_FAST = FALSE # was not used in call to my_install
MY_INSTALL_DESTINATION = "bin"
MY_INSTALL_RENAME <UNDEFINED> # was not used
MY_INSTALL_TARGETS = "foo;bar"
MY_INSTALL_CONFIGURATIONS <UNDEFINED> # was not used
MY_INSTALL_UNPARSED_ARGUMENTS = "blub" # nothing expected after "OPTIONAL"
MY_INSTALL_KEYWORDS_MISSING_VALUES = "CONFIGURATIONS"
# No value for "CONFIGURATIONS" given
You can then continue and process these variables.
Keywords terminate lists of values, e.g. if directly after a one_value_keyword another recognized keyword
follows, this is interpreted as the beginning of the new option. E.g. my_install(TARGETS foo
DESTINATION OPTIONAL) would result in MY_INSTALL_DESTINATION set to "OPTIONAL", but as OPTIONAL is a
keyword itself MY_INSTALL_DESTINATION will be empty (but added to MY_INSTALL_KEYWORDS_MISSING_VALUES) and
MY_INSTALL_OPTIONAL will therefore be set to TRUE.
cmake_path
New in version 3.20.
This command is for the manipulation of paths. Only syntactic aspects of paths are handled, there is no
interaction of any kind with any underlying file system. The path may represent a non-existing path or
even one that is not allowed to exist on the current file system or platform. For operations that do
interact with the filesystem, see the file() command.
NOTE:
The cmake_path command handles paths in the format of the build system (i.e. the host platform), not
the target system. When cross-compiling, if the path contains elements that are not representable on
the host platform (e.g. a drive letter when the host is not Windows), the results will be
unpredictable.
Synopsis
Conventions
Path Structure And Terminology
Normalization
Decomposition
cmake_path(GET <path-var> ROOT_NAME <out-var>)
cmake_path(GET <path-var> ROOT_DIRECTORY <out-var>)
cmake_path(GET <path-var> ROOT_PATH <out-var>)
cmake_path(GET <path-var> FILENAME <out-var>)
cmake_path(GET <path-var> EXTENSION [LAST_ONLY] <out-var>)
cmake_path(GET <path-var> STEM [LAST_ONLY] <out-var>)
cmake_path(GET <path-var> RELATIVE_PART <out-var>)
cmake_path(GET <path-var> PARENT_PATH <out-var>)
Query
cmake_path(HAS_ROOT_NAME <path-var> <out-var>)
cmake_path(HAS_ROOT_DIRECTORY <path-var> <out-var>)
cmake_path(HAS_ROOT_PATH <path-var> <out-var>)
cmake_path(HAS_FILENAME <path-var> <out-var>)
cmake_path(HAS_EXTENSION <path-var> <out-var>)
cmake_path(HAS_STEM <path-var> <out-var>)
cmake_path(HAS_RELATIVE_PART <path-var> <out-var>)
cmake_path(HAS_PARENT_PATH <path-var> <out-var>)
cmake_path(IS_ABSOLUTE <path-var> <out-var>)
cmake_path(IS_RELATIVE <path-var> <out-var>)
cmake_path(IS_PREFIX <path-var> <input> [NORMALIZE] <out-var>)
cmake_path(COMPARE <input1> <OP> <input2> <out-var>)
Modification
cmake_path(SET <path-var> [NORMALIZE] <input>)
cmake_path(APPEND <path-var> [<input>...] [OUTPUT_VARIABLE <out-var>])
cmake_path(APPEND_STRING <path-var> [<input>...] [OUTPUT_VARIABLE <out-var>])
cmake_path(REMOVE_FILENAME <path-var> [OUTPUT_VARIABLE <out-var>])
cmake_path(REPLACE_FILENAME <path-var> <input> [OUTPUT_VARIABLE <out-var>])
cmake_path(REMOVE_EXTENSION <path-var> [LAST_ONLY] [OUTPUT_VARIABLE <out-var>])
cmake_path(REPLACE_EXTENSION <path-var> [LAST_ONLY] <input> [OUTPUT_VARIABLE <out-var>])
Generation
cmake_path(NORMAL_PATH <path-var> [OUTPUT_VARIABLE <out-var>])
cmake_path(RELATIVE_PATH <path-var> [BASE_DIRECTORY <input>] [OUTPUT_VARIABLE <out-var>])
cmake_path(ABSOLUTE_PATH <path-var> [BASE_DIRECTORY <input>] [NORMALIZE] [OUTPUT_VARIABLE <out-var>])
Native Conversion
cmake_path(NATIVE_PATH <path-var> [NORMALIZE] <out-var>)
cmake_path(CONVERT <input> TO_CMAKE_PATH_LIST <out-var> [NORMALIZE])
cmake_path(CONVERT <input> TO_NATIVE_PATH_LIST <out-var> [NORMALIZE])
Hashing
cmake_path(HASH <path-var> <out-var>)
Conventions
The following conventions are used in this command's documentation:
<path-var>
Always the name of a variable. For commands that expect a <path-var> as input, the variable must
exist and it is expected to hold a single path.
<input>
A string literal which may contain a path, path fragment, or multiple paths with a special
separator depending on the command. See the description of each command to see how this is
interpreted.
<input>...
Zero or more string literal arguments.
<out-var>
The name of a variable into which the result of a command will be written.
Path Structure And Terminology
A path has the following structure (all components are optional, with some constraints):
root-name root-directory-separator (item-name directory-separator)* filename
root-name
Identifies the root on a filesystem with multiple roots (such as "C:" or "//myserver"). It is
optional.
root-directory-separator
A directory separator that, if present, indicates that this path is absolute. If it is missing
and the first element other than the root-name is an item-name, then the path is relative.
item-name
A sequence of characters that aren't directory separators. This name may identify a file, a hard
link, a symbolic link, or a directory. Two special cases are recognized:
• The item name consisting of a single dot character . is a directory name that refers to the
current directory.
• The item name consisting of two dot characters .. is a directory name that refers to the
parent directory.
The (...)* pattern shown above is to indicate that there can be zero or more item names, with
multiple items separated by a directory-separator. The ()* characters are not part of the path.
directory-separator
The only recognized directory separator is a forward slash character /. If this character is
repeated, it is treated as a single directory separator. In other words, /usr///////lib is the
same as /usr/lib.
filename
A path has a filename if it does not end with a directory-separator. The filename is effectively
the last item-name of the path, so it can also be a hard link, symbolic link or a directory.
A filename can have an extension. By default, the extension is defined as the sub-string
beginning at the left-most period (including the period) and until the end of the filename. In
commands that accept a LAST_ONLY keyword, LAST_ONLY changes the interpretation to the sub-string
beginning at the right-most period.
The following exceptions apply to the above interpretation:
• If the first character in the filename is a period, that period is ignored (i.e. a filename
like ".profile" is treated as having no extension).
• If the filename is either . or .., it has no extension.
The stem is the part of the filename before the extension.
Some commands refer to a root-path. This is the concatenation of root-name and root-directory-separator,
either or both of which can be empty. A relative-part refers to the full path with any root-path
removed.
Creating A Path Variable
While a path can be created with care using an ordinary set() command, it is recommended to use
cmake_path(SET) instead, as it automatically converts the path to the required form where required. The
cmake_path(APPEND) subcommand may be another suitable alternative where a path needs to be constructed by
joining fragments. The following example compares the three methods for constructing the same path:
set(path1 "${CMAKE_CURRENT_SOURCE_DIR}/data")
cmake_path(SET path2 "${CMAKE_CURRENT_SOURCE_DIR}/data")
cmake_path(APPEND path3 "${CMAKE_CURRENT_SOURCE_DIR}" "data")
Modification and Generation sub-commands can either store the result in-place, or in a separate variable
named after an OUTPUT_VARIABLE keyword. All other sub-commands store the result in a mandatory <out-var>
variable.
Normalization
Some sub-commands support normalizing a path. The algorithm used to normalize a path is as follows:
1. If the path is empty, stop (the normalized form of an empty path is also an empty path).
2. Replace each directory-separator, which may consist of multiple separators, with a single / (/a///b
--> /a/b).
3. Remove each solitary period (.) and any immediately following directory-separator (/a/./b/. --> /a/b).
4. Remove each item-name (other than ..) that is immediately followed by a directory-separator and a ..,
along with any immediately following directory-separator (/a/b/../c --> a/c).
5. If there is a root-directory, remove any .. and any directory-separators immediately following them.
The parent of the root directory is treated as still the root directory (/../a --> /a).
6. If the last item-name is .., remove any trailing directory-separator (../ --> ..).
7. If the path is empty by this stage, add a dot (normal form of ./ is .).
Decomposition
The following forms of the GET subcommand each retrieve a different component or group of components from
a path. See Path Structure And Terminology for the meaning of each path component.
cmake_path(GET <path-var> ROOT_NAME <out-var>)
cmake_path(GET <path-var> ROOT_DIRECTORY <out-var>)
cmake_path(GET <path-var> ROOT_PATH <out-var>)
cmake_path(GET <path-var> FILENAME <out-var>)
cmake_path(GET <path-var> EXTENSION [LAST_ONLY] <out-var>)
cmake_path(GET <path-var> STEM [LAST_ONLY] <out-var>)
cmake_path(GET <path-var> RELATIVE_PART <out-var>)
cmake_path(GET <path-var> PARENT_PATH <out-var>)
If a requested component is not present in the path, an empty string will be stored in <out-var>. For
example, only Windows systems have the concept of a root-name, so when the host machine is non-Windows,
the ROOT_NAME subcommand will always return an empty string.
For PARENT_PATH, if the HAS_RELATIVE_PART subcommand returns false, the result is a copy of <path-var>.
Note that this implies that a root directory is considered to have a parent, with that parent being
itself. Where HAS_RELATIVE_PART returns true, the result will essentially be <path-var> with one less
element.
Root examples
set(path "c:/a")
cmake_path(GET path ROOT_NAME rootName)
cmake_path(GET path ROOT_DIRECTORY rootDir)
cmake_path(GET path ROOT_PATH rootPath)
message("Root name is \"${rootName}\"")
message("Root directory is \"${rootDir}\"")
message("Root path is \"${rootPath}\"")
Root name is "c:"
Root directory is "/"
Root path is "c:/"
Filename examples
set(path "/a/b")
cmake_path(GET path FILENAME filename)
message("First filename is \"${filename}\"")
# Trailing slash means filename is empty
set(path "/a/b/")
cmake_path(GET path FILENAME filename)
message("Second filename is \"${filename}\"")
First filename is "b"
Second filename is ""
Extension and stem examples
set(path "name.ext1.ext2")
cmake_path(GET path EXTENSION fullExt)
cmake_path(GET path STEM fullStem)
message("Full extension is \"${fullExt}\"")
message("Full stem is \"${fullStem}\"")
# Effect of LAST_ONLY
cmake_path(GET path EXTENSION LAST_ONLY lastExt)
cmake_path(GET path STEM LAST_ONLY lastStem)
message("Last extension is \"${lastExt}\"")
message("Last stem is \"${lastStem}\"")
# Special cases
set(dotPath "/a/.")
set(dotDotPath "/a/..")
set(someMorePath "/a/.some.more")
cmake_path(GET dotPath EXTENSION dotExt)
cmake_path(GET dotPath STEM dotStem)
cmake_path(GET dotDotPath EXTENSION dotDotExt)
cmake_path(GET dotDotPath STEM dotDotStem)
cmake_path(GET dotMorePath EXTENSION someMoreExt)
cmake_path(GET dotMorePath STEM someMoreStem)
message("Dot extension is \"${dotExt}\"")
message("Dot stem is \"${dotStem}\"")
message("Dot-dot extension is \"${dotDotExt}\"")
message("Dot-dot stem is \"${dotDotStem}\"")
message(".some.more extension is \"${someMoreExt}\"")
message(".some.more stem is \"${someMoreStem}\"")
Full extension is ".ext1.ext2"
Full stem is "name"
Last extension is ".ext2"
Last stem is "name.ext1"
Dot extension is ""
Dot stem is "."
Dot-dot extension is ""
Dot-dot stem is ".."
.some.more extension is ".more"
.some.more stem is ".some"
Relative part examples
set(path "c:/a/b")
cmake_path(GET path RELATIVE_PART result)
message("Relative part is \"${result}\"")
set(path "c/d")
cmake_path(GET path RELATIVE_PART result)
message("Relative part is \"${result}\"")
set(path "/")
cmake_path(GET path RELATIVE_PART result)
message("Relative part is \"${result}\"")
Relative part is "a/b"
Relative part is "c/d"
Relative part is ""
Path traversal examples
set(path "c:/a/b")
cmake_path(GET path PARENT_PATH result)
message("Parent path is \"${result}\"")
set(path "c:/")
cmake_path(GET path PARENT_PATH result)
message("Parent path is \"${result}\"")
Parent path is "c:/a"
Parent path is "c:/"
Query
Each of the GET subcommands has a corresponding HAS_... subcommand which can be used to discover whether
a particular path component is present. See Path Structure And Terminology for the meaning of each path
component.
cmake_path(HAS_ROOT_NAME <path-var> <out-var>)
cmake_path(HAS_ROOT_DIRECTORY <path-var> <out-var>)
cmake_path(HAS_ROOT_PATH <path-var> <out-var>)
cmake_path(HAS_FILENAME <path-var> <out-var>)
cmake_path(HAS_EXTENSION <path-var> <out-var>)
cmake_path(HAS_STEM <path-var> <out-var>)
cmake_path(HAS_RELATIVE_PART <path-var> <out-var>)
cmake_path(HAS_PARENT_PATH <path-var> <out-var>)
Each of the above follows the predictable pattern of setting <out-var> to true if the path has the
associated component, or false otherwise. Note the following special cases:
• For HAS_ROOT_PATH, a true result will only be returned if at least one of root-name or root-directory
is non-empty.
• For HAS_PARENT_PATH, the root directory is also considered to have a parent, which will be itself. The
result is true except if the path consists of just a filename.
cmake_path(IS_ABSOLUTE <path-var> <out-var>)
Sets <out-var> to true if <path-var> is absolute. An absolute path is a path that unambiguously
identifies the location of a file without reference to an additional starting location. On Windows, this
means the path must have both a root-name and a root-directory-separator to be considered absolute. On
other platforms, just a root-directory-separator is sufficient. Note that this means on Windows,
IS_ABSOLUTE can be false while HAS_ROOT_DIRECTORY can be true.
cmake_path(IS_RELATIVE <path-var> <out-var>)
This will store the opposite of IS_ABSOLUTE in <out-var>.
cmake_path(IS_PREFIX <path-var> <input> [NORMALIZE] <out-var>)
Checks if <path-var> is the prefix of <input>.
When the NORMALIZE option is specified, <path-var> and <input> are normalized before the check.
set(path "/a/b/c")
cmake_path(IS_PREFIX path "/a/b/c/d" result) # result = true
cmake_path(IS_PREFIX path "/a/b" result) # result = false
cmake_path(IS_PREFIX path "/x/y/z" result) # result = false
set(path "/a/b")
cmake_path(IS_PREFIX path "/a/c/../b" NORMALIZE result) # result = true
cmake_path(COMPARE <input1> EQUAL <input2> <out-var>)
cmake_path(COMPARE <input1> NOT_EQUAL <input2> <out-var>)
Compares the lexical representations of two paths provided as string literals. No normalization is
performed on either path. Equality is determined according to the following pseudo-code logic:
if(NOT <input1>.root_name() STREQUAL <input2>.root_name())
return FALSE
if(<input1>.has_root_directory() XOR <input2>.has_root_directory())
return FALSE
Return FALSE if a relative portion of <input1> is not lexicographically
equal to the relative portion of <input2>. This comparison is performed path
component-wise. If all of the components compare equal, then return TRUE.
NOTE:
Unlike most other cmake_path() subcommands, the COMPARE subcommand takes literal strings as input, not
the names of variables.
Modification
cmake_path(SET <path-var> [NORMALIZE] <input>)
Assign the <input> path to <path-var>. If <input> is a native path, it is converted into a cmake-style
path with forward-slashes (/). On Windows, the long filename marker is taken into account.
When the NORMALIZE option is specified, the path is normalized before the conversion.
For example:
set(native_path "c:\\a\\b/..\\c")
cmake_path(SET path "${native_path}")
message("CMake path is \"${path}\"")
cmake_path(SET path NORMALIZE "${native_path}")
message("Normalized CMake path is \"${path}\"")
Output:
CMake path is "c:/a/b/../c"
Normalized CMake path is "c:/a/c"
cmake_path(APPEND <path-var> [<input>...] [OUTPUT_VARIABLE <out-var>])
Append all the <input> arguments to the <path-var> using / as the directory-separator. Depending on the
<input>, the previous contents of <path-var> may be discarded. For each <input> argument, the following
algorithm (pseudo-code) applies:
# <path> is the contents of <path-var>
if(<input>.is_absolute() OR
(<input>.has_root_name() AND
NOT <input>.root_name() STREQUAL <path>.root_name()))
replace <path> with <input>
return()
endif()
if(<input>.has_root_directory())
remove any root-directory and the entire relative path from <path>
elseif(<path>.has_filename() OR
(NOT <path-var>.has_root_directory() OR <path>.is_absolute()))
append directory-separator to <path>
endif()
append <input> omitting any root-name to <path>
cmake_path(APPEND_STRING <path-var> [<input>...] [OUTPUT_VARIABLE <out-var>])
Append all the <input> arguments to the <path-var> without adding any directory-separator.
cmake_path(REMOVE_FILENAME <path-var> [OUTPUT_VARIABLE <out-var>])
Removes the filename component (as returned by GET ... FILENAME) from <path-var>. After removal, any
trailing directory-separator is left alone, if present.
If OUTPUT_VARIABLE is not given, then after this function returns, HAS_FILENAME returns false for
<path-var>.
For example:
set(path "/a/b")
cmake_path(REMOVE_FILENAME path)
message("First path is \"${path}\"")
# filename is now already empty, the following removes nothing
cmake_path(REMOVE_FILENAME path)
message("Second path is \"${result}\"")
Output:
First path is "/a/"
Second path is "/a/"
cmake_path(REPLACE_FILENAME <path-var> <input> [OUTPUT_VARIABLE <out-var>])
Replaces the filename component from <path-var> with <input>. If <path-var> has no filename component
(i.e. HAS_FILENAME returns false), the path is unchanged. The operation is equivalent to the following:
cmake_path(HAS_FILENAME path has_filename)
if(has_filename)
cmake_path(REMOVE_FILENAME path)
cmake_path(APPEND path input);
endif()
cmake_path(REMOVE_EXTENSION <path-var> [LAST_ONLY]
[OUTPUT_VARIABLE <out-var>])
Removes the extension, if any, from <path-var>.
cmake_path(REPLACE_EXTENSION <path-var> [LAST_ONLY] <input>
[OUTPUT_VARIABLE <out-var>])
Replaces the extension with <input>. Its effect is equivalent to the following:
cmake_path(REMOVE_EXTENSION path)
if(NOT "input" MATCHES "^\\.")
cmake_path(APPEND_STRING path ".")
endif()
cmake_path(APPEND_STRING path "input")
Generation
cmake_path(NORMAL_PATH <path-var> [OUTPUT_VARIABLE <out-var>])
Normalize <path-var> according the steps described in Normalization.
cmake_path(RELATIVE_PATH <path-var> [BASE_DIRECTORY <input>]
[OUTPUT_VARIABLE <out-var>])
Modifies <path-var> to make it relative to the BASE_DIRECTORY argument. If BASE_DIRECTORY is not
specified, the default base directory will be CMAKE_CURRENT_SOURCE_DIR.
For reference, the algorithm used to compute the relative path is the same as that used by C++
std::filesystem::path::lexically_relative.
cmake_path(ABSOLUTE_PATH <path-var> [BASE_DIRECTORY <input>] [NORMALIZE]
[OUTPUT_VARIABLE <out-var>])
If <path-var> is a relative path (IS_RELATIVE is true), it is evaluated relative to the given base
directory specified by BASE_DIRECTORY option. If BASE_DIRECTORY is not specified, the default base
directory will be CMAKE_CURRENT_SOURCE_DIR.
When the NORMALIZE option is specified, the path is normalized after the path computation.
Because cmake_path() does not access the filesystem, symbolic links are not resolved and any leading
tilde is not expanded. To compute a real path with symbolic links resolved and leading tildes expanded,
use the file(REAL_PATH) command instead.
Native Conversion
For commands in this section, native refers to the host platform, not the target platform when
cross-compiling.
cmake_path(NATIVE_PATH <path-var> [NORMALIZE] <out-var>)
Converts a cmake-style <path-var> into a native path with platform-specific slashes (\ on Windows hosts
and / elsewhere).
When the NORMALIZE option is specified, the path is normalized before the conversion.
cmake_path(CONVERT <input> TO_CMAKE_PATH_LIST <out-var> [NORMALIZE])
Converts a native <input> path into a cmake-style path with forward slashes (/). On Windows hosts, the
long filename marker is taken into account. The input can be a single path or a system search path like
$ENV{PATH}. A search path will be converted to a cmake-style list separated by ; characters (on
non-Windows platforms, this essentially means : separators are replaced with ;). The result of the
conversion is stored in the <out-var> variable.
When the NORMALIZE option is specified, the path is normalized before the conversion.
NOTE:
Unlike most other cmake_path() subcommands, the CONVERT subcommand takes a literal string as input,
not the name of a variable.
cmake_path(CONVERT <input> TO_NATIVE_PATH_LIST <out-var> [NORMALIZE])
Converts a cmake-style <input> path into a native path with platform-specific slashes (\ on Windows hosts
and / elsewhere). The input can be a single path or a cmake-style list. A list will be converted into a
native search path (;-separated on Windows, :-separated on other platforms). The result of the
conversion is stored in the <out-var> variable.
When the NORMALIZE option is specified, the path is normalized before the conversion.
NOTE:
Unlike most other cmake_path() subcommands, the CONVERT subcommand takes a literal string as input,
not the name of a variable.
For example:
set(paths "/a/b/c" "/x/y/z")
cmake_path(CONVERT "${paths}" TO_NATIVE_PATH_LIST native_paths)
message("Native path list is \"${native_paths}\"")
Output on Windows:
Native path list is "\a\b\c;\x\y\z"
Output on all other platforms:
Native path list is "/a/b/c:/x/y/z"
Hashing
cmake_path(HASH <path-var> <out-var>)
Compute a hash value of <path-var> such that for two paths p1 and p2 that compare equal (COMPARE ...
EQUAL), the hash value of p1 is equal to the hash value of p2. The path is always normalized before the
hash is computed.
cmake_policy
Manage CMake Policy settings. See the cmake-policies(7) manual for defined policies.
As CMake evolves it is sometimes necessary to change existing behavior in order to fix bugs or improve
implementations of existing features. The CMake Policy mechanism is designed to help keep existing
projects building as new versions of CMake introduce changes in behavior. Each new policy (behavioral
change) is given an identifier of the form CMP<NNNN> where <NNNN> is an integer index. Documentation
associated with each policy describes the OLD and NEW behavior and the reason the policy was introduced.
Projects may set each policy to select the desired behavior. When CMake needs to know which behavior to
use it checks for a setting specified by the project. If no setting is available the OLD behavior is
assumed and a warning is produced requesting that the policy be set.
Setting Policies by CMake Version
The cmake_policy command is used to set policies to OLD or NEW behavior. While setting policies
individually is supported, we encourage projects to set policies based on CMake versions:
cmake_policy(VERSION <min>[...<max>])
New in version 3.12: The optional <max> version.
<min> and the optional <max> are each CMake versions of the form major.minor[.patch[.tweak]], and the ...
is literal. The <min> version must be at least 2.4 and at most the running version of CMake. The <max>
version, if specified, must be at least the <min> version but may exceed the running version of CMake.
If the running version of CMake is older than 3.12, the extra ... dots will be seen as version component
separators, resulting in the ...<max> part being ignored and preserving the pre-3.12 behavior of basing
policies on <min>.
This specifies that the current CMake code is written for the given range of CMake versions. All
policies known to the running version of CMake and introduced in the <min> (or <max>, if specified)
version or earlier will be set to use NEW behavior. All policies introduced in later versions will be
unset (unless the CMAKE_POLICY_DEFAULT_CMP<NNNN> variable sets a default). This effectively requests
behavior preferred as of a given CMake version and tells newer CMake versions to warn about their new
policies.
Note that the cmake_minimum_required(VERSION) command implicitly calls cmake_policy(VERSION) too.
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 protect
its parents and siblings. CMake also manages a new entry for scripts loaded by include() and
find_package() commands except when invoked with the NO_POLICY_SCOPE option (see also policy CMP0011).
The cmake_policy command provides an interface to manage custom entries on the policy stack:
cmake_policy(PUSH)
cmake_policy(POP)
Each PUSH must have a matching POP to erase any changes. This is useful to make temporary changes to
policy settings. Calls to the cmake_minimum_required(VERSION), cmake_policy(VERSION), or
cmake_policy(SET) commands influence only the current top of the policy stack.
Commands created by the function() and macro() commands record policy settings when they are created and
use the pre-record policies when they are invoked. If the function or macro implementation sets
policies, the changes automatically propagate up through callers until they reach the closest nested
policy stack entry.
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
variable, or the empty string if the variable is not defined. Furthermore, input lines of the form
#cmakedefine VAR ...
will be replaced with either
#define VAR ...
or
/* #undef VAR */
depending on whether VAR is set in CMake to any value not considered a false constant by the if()
command. The "..." content on the line after the variable name, if any, is processed as above.
Unlike lines of the form #cmakedefine VAR ..., in lines of the form #cmakedefine01 VAR, VAR itself will
expand to VAR 0 or VAR 1 rather than being assigned the value .... Therefore, input lines of the form
#cmakedefine01 VAR
will be replaced with either
#define VAR 0
or
#define VAR 1
Input lines of the form #cmakedefine01 VAR ... will expand as #cmakedefine01 VAR ... 0 or #cmakedefine01
VAR ... 0, which may lead to undefined behavior.
New in version 3.10: The result lines (with the exception of the #undef comments) can be indented using
spaces and/or tabs between the # character and the cmakedefine or cmakedefine01 words. This whitespace
indentation will be preserved in the output lines:
# cmakedefine VAR
# cmakedefine01 VAR
will be replaced, if VAR is defined, with
# define VAR
# define VAR 1
If the input file is modified the build system will re-run CMake to re-configure the file and generate
the build system again. The generated file is modified and its timestamp updated on subsequent cmake
runs only if its content is changed.
The arguments are:
<input>
Path to the input file. A relative path is treated with respect to the value of
CMAKE_CURRENT_SOURCE_DIR. The input path must be a file, not a directory.
<output>
Path to the output file or directory. A relative path is treated with respect to the value of
CMAKE_CURRENT_BINARY_DIR. If the path names an existing directory the output file is placed in
that directory with the same file name as the input file. If the path contains non-existent
directories, they are created.
NO_SOURCE_PERMISSIONS
New in version 3.19.
Do not transfer the permissions of the input file to the output file. The copied file permissions
default to the standard 644 value (-rw-r--r--).
USE_SOURCE_PERMISSIONS
New in version 3.20.
Transfer the permissions of the input file to the output file. This is already the default
behavior if none of the three permissions-related keywords are given (NO_SOURCE_PERMISSIONS,
USE_SOURCE_PERMISSIONS or FILE_PERMISSIONS). The USE_SOURCE_PERMISSIONS keyword mostly serves as
a way of making the intended behavior clearer at the call site.
FILE_PERMISSIONS <permissions>...
New in version 3.20.
Ignore the input file's permissions and use the specified <permissions> for the output file
instead.
COPYONLY
Copy the file without replacing any variable references or other content. This option may not be
used with NEWLINE_STYLE.
ESCAPE_QUOTES
Escape any substituted quotes with backslashes (C-style).
@ONLY Restrict variable replacement to references of the form @VAR@. This is useful for configuring
scripts that use ${VAR} syntax.
NEWLINE_STYLE <style>
Specify the newline style for the output file. Specify UNIX or LF for \n newlines, or specify
DOS, WIN32, or CRLF for \r\n newlines. This option may not be used with COPYONLY.
Example
Consider a source tree containing a foo.h.in file:
#cmakedefine FOO_ENABLE
#cmakedefine FOO_STRING "@FOO_STRING@"
An adjacent CMakeLists.txt may use configure_file to configure the header:
option(FOO_ENABLE "Enable Foo" ON)
if(FOO_ENABLE)
set(FOO_STRING "foo")
endif()
configure_file(foo.h.in foo.h @ONLY)
This creates a foo.h in the build directory corresponding to this source directory. If the FOO_ENABLE
option is on, the configured file will contain:
#define FOO_ENABLE
#define FOO_STRING "foo"
Otherwise it will contain:
/* #undef FOO_ENABLE */
/* #undef FOO_STRING */
One may then use the include_directories() command to specify the output directory as an include
directory:
include_directories(${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 a block in a foreach() or while() loop,
and start at the top of the next iteration.
See also the break() command.
else
Starts the else portion of an if block.
else([<condition>])
See the if() command.
elseif
Starts an elseif portion of an if block.
elseif(<condition>)
See the if() command, especially for the syntax and logic of the <condition>.
endforeach
Ends a list of commands in a foreach block.
endforeach([<loop_var>])
See the foreach() command.
The optional <loop_var> argument is supported for backward compatibility only. If used it must be a
verbatim repeat of the <loop_var> argument of the opening foreach clause.
endfunction
Ends a list of commands in a function block.
endfunction([<name>])
See the function() command.
The optional <name> argument is supported for backward compatibility only. If used it must be a verbatim
repeat of the <name> argument of the opening function command.
endif
Ends a list of commands in an if block.
endif([<condition>])
See the if() command.
The optional <condition> argument is supported for backward compatibility only. If used it must be a
verbatim repeat of the argument of the opening if clause.
endmacro
Ends a list of commands in a macro block.
endmacro([<name>])
See the macro() command.
The optional <name> argument is supported for backward compatibility only. If used it must be a verbatim
repeat of the <name> argument of the opening macro command.
endwhile
Ends a list of commands in a while block.
endwhile([<condition>])
See the while() command.
The optional <condition> argument is supported for backward compatibility only. If used it must be a
verbatim repeat of the argument of the opening while clause.
execute_process
Execute one or more child processes.
execute_process(COMMAND <cmd1> [<arguments>]
[COMMAND <cmd2> [<arguments>]]...
[WORKING_DIRECTORY <directory>]
[TIMEOUT <seconds>]
[RESULT_VARIABLE <variable>]
[RESULTS_VARIABLE <variable>]
[OUTPUT_VARIABLE <variable>]
[ERROR_VARIABLE <variable>]
[INPUT_FILE <file>]
[OUTPUT_FILE <file>]
[ERROR_FILE <file>]
[OUTPUT_QUIET]
[ERROR_QUIET]
[COMMAND_ECHO <where>]
[OUTPUT_STRIP_TRAILING_WHITESPACE]
[ERROR_STRIP_TRAILING_WHITESPACE]
[ENCODING <name>]
[ECHO_OUTPUT_VARIABLE]
[ECHO_ERROR_VARIABLE]
[COMMAND_ERROR_IS_FATAL <ANY|LAST>])
Runs the given sequence of one or more commands.
Commands are executed concurrently as a pipeline, with the standard output of each process piped to the
standard input of the next. A single standard error pipe is used for all processes.
Options:
COMMAND
A child process command line.
CMake executes the child process using operating system APIs directly. All arguments are passed
VERBATIM to the child process. 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 RESULT_VARIABLE will be set to a string mentioning the "timeout".
RESULT_VARIABLE
The variable will be set to contain the result of last child process. This will be an integer
return code from the last child or a string describing an error condition.
RESULTS_VARIABLE <variable>
New in version 3.10.
The variable will be set to contain the result of all processes as a semicolon-separated list, in
order of the given COMMAND arguments. Each entry will be an integer return code from the
corresponding child or a string describing an error condition.
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 output is encoded in the same way as
CMake's internal encoding (UTF-8). This is the default.
AUTO Use the current active console's codepage or if that isn't available then use ANSI.
ANSI Use the ANSI codepage.
OEM Use the original equipment manufacturer (OEM) code page.
UTF8 or UTF-8
Use the UTF-8 codepage.
New in version 3.11: Accept UTF-8 spelling for consistency with the UTF-8 RFC naming
convention.
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 configured 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 behavior when an error is encountered:
ANY If any of the commands in the list of commands fail, the execute_process() command halts
with an error.
LAST If the last command in the list of commands fails, the execute_process() command halts
with an error. Commands earlier in the list will not cause a fatal error.
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 access to the filesystem.
For other path manipulation, handling only syntactic aspects, have a look at cmake_path() command.
NOTE:
The sub-commands RELATIVE_PATH, TO_CMAKE_PATH and TO_NATIVE_PATH has been superseded, respectively, by
sub-commands RELATIVE_PATH, CONVERT ... TO_CMAKE_PATH_LIST and CONVERT ... TO_NATIVE_PATH_LIST of
cmake_path() command.
Synopsis
Reading
file(READ <filename> <out-var> [...])
file(STRINGS <filename> <out-var> [...])
file(<HASH> <filename> <out-var>)
file(TIMESTAMP <filename> <out-var> [...])
file(GET_RUNTIME_DEPENDENCIES [...])
Writing
file({WRITE | APPEND} <filename> <content>...)
file({TOUCH | TOUCH_NOCREATE} [<file>...])
file(GENERATE OUTPUT <output-file> [...])
file(CONFIGURE OUTPUT <output-file> CONTENT <content> [...])
Filesystem
file({GLOB | GLOB_RECURSE} <out-var> [...] [<globbing-expr>...])
file(MAKE_DIRECTORY [<dir>...])
file({REMOVE | REMOVE_RECURSE } [<files>...])
file(RENAME <oldname> <newname> [...])
file(COPY_FILE <oldname> <newname> [...])
file({COPY | INSTALL} <file>... DESTINATION <dir> [...])
file(SIZE <filename> <out-var>)
file(READ_SYMLINK <linkname> <out-var>)
file(CREATE_LINK <original> <linkname> [...])
file(CHMOD <files>... <directories>... PERMISSIONS <permissions>... [...])
file(CHMOD_RECURSE <files>... <directories>... PERMISSIONS <permissions>... [...])
Path Conversion
file(REAL_PATH <path> <out-var> [BASE_DIRECTORY <dir>] [EXPAND_TILDE])
file(RELATIVE_PATH <out-var> <directory> <file>)
file({TO_CMAKE_PATH | TO_NATIVE_PATH} <path> <out-var>)
Transfer
file(DOWNLOAD <url> [<file>] [...])
file(UPLOAD <file> <url> [...])
Locking
file(LOCK <path> [...])
Archiving
file(ARCHIVE_CREATE OUTPUT <archive> PATHS <paths>... [...])
file(ARCHIVE_EXTRACT INPUT <archive> [...])
Reading
file(READ <filename> <variable>
[OFFSET <offset>] [LIMIT <max-in>] [HEX])
Read content from a file called <filename> and store it in a <variable>. Optionally start from the given
<offset> and read at most <max-in> bytes. The HEX option causes data to be converted to a hexadecimal
representation (useful for binary data). If the HEX option is specified, letters in the output (a through
f) are in lowercase.
file(STRINGS <filename> <variable> [<options>...])
Parse a list of ASCII strings from <filename> and store it in <variable>. Binary data in the file are
ignored. Carriage return (\r, CR) characters are ignored. The options are:
LENGTH_MAXIMUM <max-len>
Consider only strings of at most a given length.
LENGTH_MINIMUM <min-len>
Consider only strings of at least a given length.
LIMIT_COUNT <max-num>
Limit the number of distinct strings to be extracted.
LIMIT_INPUT <max-in>
Limit the number of input bytes to read from the file.
LIMIT_OUTPUT <max-out>
Limit the number of total bytes to store in the <variable>.
NEWLINE_CONSUME
Treat newline characters (\n, LF) as part of string content instead of terminating at them.
NO_HEX_CONVERSION
Intel Hex and Motorola S-record files are automatically converted to binary while reading unless
this option is given.
REGEX <regex>
Consider only strings that match the given regular expression, as described under string(REGEX).
ENCODING <encoding-type>
New in version 3.1.
Consider strings of a given encoding. Currently supported encodings are: UTF-8, UTF-16LE,
UTF-16BE, UTF-32LE, UTF-32BE. If the ENCODING option is not provided and the file has a Byte
Order Mark, the ENCODING option will be defaulted to respect the Byte Order Mark.
New in version 3.2: Added the UTF-16LE, UTF-16BE, UTF-32LE, UTF-32BE encodings.
For example, the code
file(STRINGS myfile.txt myfile)
stores a list in the variable myfile in which each item is a line from the input file.
file(<HASH> <filename> <variable>)
Compute a cryptographic hash of the content of <filename> and store it in a <variable>. The supported
<HASH> algorithm names are those listed by the string(<HASH>) command.
file(TIMESTAMP <filename> <variable> [<format>] [UTC])
Compute a string representation of the modification time of <filename> and store it in <variable>.
Should the command be unable to obtain a timestamp variable will be set to the empty string ("").
See the string(TIMESTAMP) command for documentation of the <format> and UTC options.
file(GET_RUNTIME_DEPENDENCIES
[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 generated by the install(RUNTIME_DEPENDENCY_SET) command, or from code
provided by the project via install(CODE) or install(SCRIPT). For example:
install(CODE [[
file(GET_RUNTIME_DEPENDENCIES
# ...
)
]])
The arguments are as follows:
RESOLVED_DEPENDENCIES_VAR <deps_var>
Name of the variable in which to store the list of resolved dependencies.
UNRESOLVED_DEPENDENCIES_VAR <unresolved_deps_var>
Name of the variable in which to store the list of unresolved dependencies. If this variable is
not specified, and there are any unresolved dependencies, an error is issued.
CONFLICTING_DEPENDENCIES_PREFIX <conflicting_deps_prefix>
Variable prefix in which to store conflicting dependency information. Dependencies are
conflicting if two files with the same name are found in two different directories. The list of
filenames that conflict are stored in <conflicting_deps_prefix>_FILENAMES. For each filename, the
list of paths that were found for that filename are stored in
<conflicting_deps_prefix>_<filename>.
EXECUTABLES <executable_files>
List of executable files to read for dependencies. These are executables that are typically
created with add_executable(), but they do not have to be created by CMake. On Apple platforms,
the paths to these files determine the value of @executable_path when recursively resolving the
libraries. Specifying any kind of library (STATIC, MODULE, or SHARED) here will result in
undefined behavior.
LIBRARIES <library_files>
List of library files to read for dependencies. These are libraries that are typically created
with add_library(SHARED), but they do not have to be created by CMake. Specifying STATIC
libraries, MODULE libraries, or executables here will result in undefined behavior.
MODULES <module_files>
List of loadable module files to read for dependencies. These are modules that are typically
created with add_library(MODULE), but they do not have to be created by CMake. They are typically
used by calling dlopen() at runtime rather than linked at link time with ld -l. Specifying STATIC
libraries, SHARED libraries, or executables here will result in undefined behavior.
DIRECTORIES <directories>
List of additional directories to search for dependencies. On Linux platforms, these directories
are searched if the dependency is not found in any of the other usual paths. If it is found in
such a directory, a warning is issued, because it means that the file is incomplete (it does not
list all of the directories that contain its dependencies). On Windows platforms, these
directories are searched if the dependency is not found in any of the other search paths, but no
warning is issued, because searching other paths is a normal part of Windows dependency
resolution. On Apple platforms, this argument has no effect.
BUNDLE_EXECUTABLE <bundle_executable_file>
Executable to treat as the "bundle executable" when resolving libraries. On Apple platforms, this
argument determines the value of @executable_path when recursively resolving libraries for
LIBRARIES and MODULES files. It has no effect on EXECUTABLES files. On other platforms, it has no
effect. This is typically (but not always) one of the executables in the EXECUTABLES argument
which designates the "main" executable of the package.
The following arguments specify filters for including or excluding libraries to be resolved. See below
for a full description of how they work.
PRE_INCLUDE_REGEXES <regexes>
List of pre-include regexes through which to filter the names of not-yet-resolved dependencies.
PRE_EXCLUDE_REGEXES <regexes>
List of pre-exclude regexes through which to filter the names of not-yet-resolved dependencies.
POST_INCLUDE_REGEXES <regexes>
List of post-include regexes through which to filter the names of resolved dependencies.
POST_EXCLUDE_REGEXES <regexes>
List of post-exclude regexes through which to filter the names of resolved dependencies.
POST_INCLUDE_FILES <files>
New in version 3.21.
List of post-include filenames through which to filter the names of resolved dependencies.
Symlinks are resolved when attempting to match these filenames.
POST_EXCLUDE_FILES <files>
New in version 3.21.
List of post-exclude filenames through which to filter the names of resolved dependencies.
Symlinks are resolved when attempting to match these filenames.
These arguments can be used to exclude unwanted system libraries when resolving the dependencies, or to
include libraries from a specific directory. The filtering works as follows:
1. If the not-yet-resolved dependency matches any of the PRE_INCLUDE_REGEXES, steps 2 and 3 are skipped,
and the dependency resolution proceeds to step 4.
2. If the not-yet-resolved dependency matches any of the PRE_EXCLUDE_REGEXES, dependency resolution stops
for that dependency.
3. Otherwise, dependency resolution proceeds.
4. file(GET_RUNTIME_DEPENDENCIES) searches for the dependency according to the linking rules of the
platform (see below).
5. If the dependency is found, and its full path matches one of the POST_INCLUDE_REGEXES or
POST_INCLUDE_FILES, the full path is added to the resolved dependencies, and
file(GET_RUNTIME_DEPENDENCIES) recursively resolves that library's own dependencies. Otherwise,
resolution proceeds to step 6.
6. If the dependency is found, but its full path matches one of the POST_EXCLUDE_REGEXES or
POST_EXCLUDE_FILES, it is not added to the resolved dependencies, and dependency resolution stops for
that dependency.
7. If the dependency is found, and its full path does not match either POST_INCLUDE_REGEXES,
POST_INCLUDE_FILES, POST_EXCLUDE_REGEXES, or POST_EXCLUDE_FILES, the full path is added to the
resolved dependencies, and file(GET_RUNTIME_DEPENDENCIES) recursively resolves that library's own
dependencies.
Different platforms have different rules for how dependencies are resolved. These specifics are
described here.
On Linux platforms, library resolution works as follows:
1. If the depending file does not have any RUNPATH entries, and the library exists in one of the
depending file's RPATH entries, or its parents', in that order, the dependency is resolved to that
file.
2. Otherwise, if the depending file has any RUNPATH entries, and the library exists in one of those
entries, the dependency is resolved to that file.
3. Otherwise, if the library exists in one of the directories listed by ldconfig, the dependency is
resolved to that file.
4. Otherwise, if the library exists in one of the DIRECTORIES entries, the dependency is resolved to that
file. In this case, a warning is issued, because finding a file in one of the DIRECTORIES means that
the depending file is not complete (it does not list all the directories from which it pulls
dependencies).
5. Otherwise, the dependency is unresolved.
On Windows platforms, library resolution works as follows:
1. 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_INCLUDE_REGEXES, PRE_EXCLUDE_REGEXES, POST_INCLUDE_REGEXES, and POST_EXCLUDE_REGEXES to properly
filter DLL names - every regex would have to check for both uppercase and lowercase letters. For
example:
file(GET_RUNTIME_DEPENDENCIES
# ...
PRE_INCLUDE_REGEXES "^[Mm][Yy][Ll][Ii][Bb][Rr][Aa][Rr][Yy]\\.[Dd][Ll][Ll]$"
)
Converting the DLL name to lowercase allows the regexes to only match lowercase names, thus
simplifying the regex. For example:
file(GET_RUNTIME_DEPENDENCIES
# ...
PRE_INCLUDE_REGEXES "^mylibrary\\.dll$"
)
This regex will match mylibrary.dll regardless of how it is cased, either on disk or in the depending
file. (For example, it will match mylibrary.dll, MyLibrary.dll, and MYLIBRARY.DLL.)
Please note that the directory portion of any resolved DLLs retains its casing and is not converted to
lowercase. Only the filename portion 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 depending file, the dependency is
resolved to that file.
4. Otherwise, if the library exists in either the operating system's system32 directory or the Windows
directory, in that order, the dependency is resolved to that file.
5. Otherwise, if the library exists in one of the directories specified by DIRECTORIES, in the order they
are listed, the dependency is resolved to that file. In this case, a warning is not issued, because
searching other directories is a normal part of Windows library resolution.
6. Otherwise, the dependency is unresolved.
On Apple platforms, library resolution works as follows:
1. If the dependency starts with @executable_path/, and an EXECUTABLES argument is in the process of
being resolved, and replacing @executable_path/ with the directory of the executable yields an
existing file, the dependency is resolved to that file.
2. Otherwise, if the dependency starts with @executable_path/, and there is a BUNDLE_EXECUTABLE argument,
and replacing @executable_path/ with the directory of the bundle executable yields an existing file,
the dependency is resolved to that file.
3. Otherwise, if the dependency starts with @loader_path/, and replacing @loader_path/ with the directory
of the depending file yields an existing file, the dependency is resolved to that file.
4. Otherwise, if the dependency starts with @rpath/, and replacing @rpath/ with one of the RPATH entries
of the depending file yields an existing file, the dependency is resolved to that file. Note that
RPATH entries that start with @executable_path/ or @loader_path/ also have these items replaced with
the appropriate path.
5. Otherwise, if the dependency is an absolute file that exists, the dependency is resolved to that file.
6. Otherwise, the dependency is unresolved.
This function accepts several variables that determine which tool is used for dependency resolution:
CMAKE_GET_RUNTIME_DEPENDENCIES_PLATFORM
Determines which operating system and executable format the files are built for. This could be one
of several values:
• linux+elf
• windows+pe
• macos+macho
If this variable is not specified, it is determined automatically by system introspection.
CMAKE_GET_RUNTIME_DEPENDENCIES_TOOL
Determines the tool to use for dependency resolution. It could be one of several values, depending
on the value of CMAKE_GET_RUNTIME_DEPENDENCIES_PLATFORM:
┌────────────────────────────────────────┬─────────────────────────────────────┐
│CMAKE_GET_RUNTIME_DEPENDENCIES_PLATFORM │ CMAKE_GET_RUNTIME_DEPENDENCIES_TOOL │
├────────────────────────────────────────┼─────────────────────────────────────┤
│linux+elf │ objdump │
├────────────────────────────────────────┼─────────────────────────────────────┤
│windows+pe │ dumpbin │
├────────────────────────────────────────┼─────────────────────────────────────┤
│windows+pe │ objdump │
├────────────────────────────────────────┼─────────────────────────────────────┤
│macos+macho │ otool │
└────────────────────────────────────────┴─────────────────────────────────────┘
If this variable is not specified, it is determined automatically by system introspection.
CMAKE_GET_RUNTIME_DEPENDENCIES_COMMAND
Determines the path to the tool to use for dependency resolution. This is the actual path to
objdump, dumpbin, or otool.
If this variable is not specified, it is determined by the value of CMAKE_OBJDUMP if set, else by
system introspection.
New in version 3.18: Use CMAKE_OBJDUMP if set.
Writing
file(WRITE <filename> <content>...)
file(APPEND <filename> <content>...)
Write <content> into a file called <filename>. If the file does not exist, it will be created. If the
file already exists, WRITE mode will overwrite it and APPEND mode will append to the end. Any
directories in the path specified by <filename> that do not exist will be created.
If the file is a build input, use the configure_file() command to update the file only when its content
changes.
file(TOUCH [<files>...])
file(TOUCH_NOCREATE [<files>...])
New in version 3.12.
Create a file with no content if it does not yet exist. If the file already exists, its access and/or
modification will be updated to the time when the function call is executed.
Use TOUCH_NOCREATE to touch a file if it exists but not create it. If a file does not exist it will be
silently ignored.
With TOUCH and TOUCH_NOCREATE the contents of an existing file will not be modified.
file(GENERATE 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 after evaluating generator expressions.
CONTENT <content>
Use the content given explicitly as input.
INPUT <input-file>
Use the content from a given file as input.
Changed in version 3.10: A relative path is treated with respect to the value of
CMAKE_CURRENT_SOURCE_DIR. See policy CMP0070.
OUTPUT <output-file>
Specify the output file name to generate. Use generator expressions such as $<CONFIG> to specify
a configuration-specific output file name. Multiple configurations may generate the same output
file only if the generated content is identical. Otherwise, the <output-file> must evaluate to an
unique name for each configuration.
Changed in version 3.10: A relative path (after evaluating generator expressions) is treated with
respect to the value of CMAKE_CURRENT_BINARY_DIR. See policy CMP0070.
TARGET <target>
New in version 3.19.
Specify which target to use when evaluating generator expressions that require a target for
evaluation (e.g. $<COMPILE_FEATURES:...>, $<TARGET_PROPERTY:prop>).
NO_SOURCE_PERMISSIONS
New in version 3.20.
The generated file permissions default to the standard 644 value (-rw-r--r--).
USE_SOURCE_PERMISSIONS
New in version 3.20.
Transfer the file permissions of the INPUT file to the generated file. This is already the
default behavior if none of the three permissions-related keywords are given
(NO_SOURCE_PERMISSIONS, USE_SOURCE_PERMISSIONS or FILE_PERMISSIONS). The USE_SOURCE_PERMISSIONS
keyword mostly serves as a way of making the intended behavior clearer at the call site. It is an
error to specify this option without INPUT.
FILE_PERMISSIONS <permissions>...
New in version 3.20.
Use the specified permissions for the generated file.
NEWLINE_STYLE <style>
New in version 3.20.
Specify the newline style for the generated file. Specify UNIX or LF for \n newlines, or specify
DOS, WIN32, or CRLF for \r\n newlines.
Exactly one CONTENT or INPUT option must be given. A specific OUTPUT file may be named by at most one
invocation of file(GENERATE). Generated files are modified and their timestamp updated on subsequent
cmake runs only if their content is changed.
Note also that file(GENERATE) does not create the output file until the generation phase. The output file
will not yet have been written when the file(GENERATE) command returns, it is written only after
processing all of a project's CMakeLists.txt files.
file(CONFIGURE OUTPUT output-file
CONTENT content
[ESCAPE_QUOTES] [@ONLY]
[NEWLINE_STYLE [UNIX|DOS|WIN32|LF|CRLF] ])
New in version 3.18.
Generate an output file using the input given by CONTENT and substitute variable values referenced as
@VAR@ or ${VAR} contained therein. The substitution rules behave the same as the configure_file()
command. In order to match configure_file()'s behavior, generator expressions are not supported for both
OUTPUT and CONTENT.
The arguments are:
OUTPUT <output-file>
Specify the output file name to generate. A relative path is treated with respect to the value of
CMAKE_CURRENT_BINARY_DIR. <output-file> does not support generator expressions.
CONTENT <content>
Use the content given explicitly as input. <content> does not support generator expressions.
ESCAPE_QUOTES
Escape any substituted quotes with backslashes (C-style).
@ONLY Restrict variable replacement to references of the form @VAR@. This is useful for configuring
scripts that use ${VAR} syntax.
NEWLINE_STYLE <style>
Specify the newline style for the output file. Specify UNIX or LF for \n newlines, or specify
DOS, WIN32, or CRLF for \r\n newlines.
Filesystem
file(GLOB <variable>
[LIST_DIRECTORIES true|false] [RELATIVE <path>] [CONFIGURE_DEPENDS]
[<globbing-expressions>...])
file(GLOB_RECURSE <variable> [FOLLOW_SYMLINKS]
[LIST_DIRECTORIES true|false] [RELATIVE <path>] [CONFIGURE_DEPENDS]
[<globbing-expressions>...])
Generate a list of files that match the <globbing-expressions> and store it into the <variable>.
Globbing expressions are similar to regular expressions, but much simpler. If RELATIVE flag is
specified, the results will be returned as relative paths to the given path.
Changed in version 3.6: The results will be ordered lexicographically.
On Windows and macOS, globbing is case-insensitive even if the underlying filesystem is case-sensitive
(both filenames and globbing expressions are converted to lowercase before matching). On other
platforms, globbing is case-sensitive.
New in version 3.3: By default GLOB lists directories - directories are omitted in result if
LIST_DIRECTORIES is set to false.
New in version 3.12: If the CONFIGURE_DEPENDS flag is specified, CMake will add logic to the main build
system check target to rerun the flagged GLOB commands at build time. If any of the outputs change, CMake
will regenerate the build system.
NOTE:
We do not recommend using GLOB to collect a list of source files from your source tree. If no
CMakeLists.txt file changes when a source is added or removed then the generated build system cannot
know when to ask CMake to regenerate. The CONFIGURE_DEPENDS flag may not work reliably on all
generators, or if a new generator is added in the future that cannot support it, projects using it
will be stuck. Even if CONFIGURE_DEPENDS works reliably, there is still a cost to perform the check on
every rebuild.
Examples of globbing expressions include:
*.cxx - match all files with extension cxx
*.vt? - match all files with extension vta,...,vtz
f[3-5].txt - match files f3.txt, f4.txt, f5.txt
The GLOB_RECURSE mode will traverse all the subdirectories of the matched directory and match the files.
Subdirectories that are symlinks are only traversed if FOLLOW_SYMLINKS is given or policy CMP0009 is not
set to NEW.
New in version 3.3: By default GLOB_RECURSE omits directories from result list - setting LIST_DIRECTORIES
to true adds directories to result list. If FOLLOW_SYMLINKS is given or policy CMP0009 is not set to NEW
then LIST_DIRECTORIES treats symlinks as directories.
Examples of recursive globbing include:
/dir/*.py - match all python files in /dir and subdirectories
file(MAKE_DIRECTORY [<directories>...])
Create the given directories and their parents as needed.
file(REMOVE [<files>...])
file(REMOVE_RECURSE [<files>...])
Remove the given files. The REMOVE_RECURSE mode will remove the given files and directories, 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 <newname>, replacing the destination
atomically.
The options are:
RESULT <result>
New in version 3.21.
Set <result> variable to 0 on success or an error message otherwise. If RESULT is not specified
and the operation fails, an error is emitted.
NO_REPLACE
New in version 3.21.
If the <newname> path already exists, do not replace it. If RESULT <result> is used, the result
variable will be set to NO_REPLACE. Otherwise, an error is emitted.
file(COPY_FILE <oldname> <newname>
[RESULT <result>]
[ONLY_IF_DIFFERENT])
New in version 3.21.
Copy a file from <oldname> to <newname>. Directories are not supported. Symlinks are ignored and
<oldfile>'s content is read and written to <newname> as a new file.
The options are:
RESULT <result>
Set <result> variable to 0 on success or an error message otherwise. If RESULT is not specified
and the operation fails, an error is emitted.
ONLY_IF_DIFFERENT
If the <newname> path already exists, do not replace it if the file's contents are already the
same as <oldname> (this avoids updating <newname>'s timestamp).
This sub-command has some similarities to configure_file() with the COPYONLY option. An important
difference is that configure_file() creates a dependency on the source file, so CMake will be re-run if
it changes. The file(COPY_FILE) sub-command does not create such a dependency.
See also the file(COPY) sub-command just below which provides further file-copying capabilities.
file(<COPY|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 destination folder. Relative input paths
are evaluated with respect to the current source directory, and a relative destination is evaluated with
respect to the current build directory. Copying preserves input file timestamps, and optimizes out a
file if it exists at the destination with the same timestamp. Copying preserves input permissions unless
explicit permissions or NO_SOURCE_PERMISSIONS are given (default is USE_SOURCE_PERMISSIONS).
New in version 3.15: If FOLLOW_SYMLINK_CHAIN is specified, COPY will recursively resolve the symlinks at
the paths given until a real file is found, and install a corresponding symlink in the destination for
each symlink encountered. For each symlink that is installed, the resolution is stripped of the
directory, leaving only the filename, meaning that the new symlink points to a file in the same directory
as the symlink. This feature is useful on some Unix systems, where libraries are installed as a chain of
symlinks with version numbers, with less specific versions pointing to more specific versions.
FOLLOW_SYMLINK_CHAIN will install all of these symlinks and the library itself into the destination
directory. For example, if you have the following directory structure:
• /opt/foo/lib/libfoo.so.1.2.3
• /opt/foo/lib/libfoo.so.1.2 -> libfoo.so.1.2.3
• /opt/foo/lib/libfoo.so.1 -> libfoo.so.1.2
• /opt/foo/lib/libfoo.so -> libfoo.so.1
and you do:
file(COPY /opt/foo/lib/libfoo.so DESTINATION lib FOLLOW_SYMLINK_CHAIN)
This will install all of the symlinks and libfoo.so.1.2.3 itself into lib.
See the install(DIRECTORY) command for documentation of permissions, FILES_MATCHING, PATTERN, REGEX, and
EXCLUDE options. Copying directories preserves the structure of their content even if options are used
to select a subset of files.
The INSTALL signature differs slightly from COPY: it prints status messages, and NO_SOURCE_PERMISSIONS is
default.
Installation scripts generated by the install() command use this signature (with some undocumented
options for internal use).
Changed in version 3.22: The environment variable CMAKE_INSTALL_MODE can override the default copying
behavior of file(INSTALL).
file(SIZE <filename> <variable>)
New in version 3.14.
Determine the file size of the <filename> and put the result in <variable> variable. Requires that
<filename> is a valid path pointing to a file and is readable.
file(READ_SYMLINK <linkname> <variable>)
New in version 3.14.
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 resolve a relative path. The following
is an example of how to ensure that an absolute path is obtained:
set(linkname "/path/to/foo.sym")
file(READ_SYMLINK "${linkname}" result)
if(NOT IS_ABSOLUTE "${result}")
get_filename_component(dir "${linkname}" DIRECTORY)
set(result "${dir}/${result}")
endif()
file(CREATE_LINK <original> <linkname>
[RESULT <result>] [COPY_ON_ERROR] [SYMBOLIC])
New in version 3.14.
Create a link <linkname> that points to <original>. It will be a hard link by default, but providing the
SYMBOLIC option results in a symbolic link instead. Hard links require that original exists and is a
file, not a directory. If <linkname> already exists, it will be overwritten.
The <result> variable, if specified, receives the status of the operation. It is set to 0 upon success
or an error message otherwise. If RESULT is not specified and the operation fails, a fatal error is
emitted.
Specifying COPY_ON_ERROR enables copying the file as a fallback if creating the link fails. It can be
useful for handling situations such as <original> and <linkname> being on different drives or mount
points, which would make them unable to support a hard link.
file(CHMOD <files>... <directories>...
[PERMISSIONS <permissions>...]
[FILE_PERMISSIONS <permissions>...]
[DIRECTORY_PERMISSIONS <permissions>...])
New in version 3.19.
Set the permissions for the <files>... and <directories>... specified. Valid permissions are
OWNER_READ, OWNER_WRITE, OWNER_EXECUTE, GROUP_READ, GROUP_WRITE, GROUP_EXECUTE, WORLD_READ, WORLD_WRITE,
WORLD_EXECUTE, SETUID, SETGID.
Valid combination of keywords are:
PERMISSIONS
All items are changed.
FILE_PERMISSIONS
Only files are changed.
DIRECTORY_PERMISSIONS
Only directories are changed.
PERMISSIONS and FILE_PERMISSIONS
FILE_PERMISSIONS overrides PERMISSIONS for files.
PERMISSIONS and DIRECTORY_PERMISSIONS
DIRECTORY_PERMISSIONS overrides PERMISSIONS for directories.
FILE_PERMISSIONS and DIRECTORY_PERMISSIONS
Use FILE_PERMISSIONS for files and DIRECTORY_PERMISSIONS for directories.
file(CHMOD_RECURSE <files>... <directories>...
[PERMISSIONS <permissions>...]
[FILE_PERMISSIONS <permissions>...]
[DIRECTORY_PERMISSIONS <permissions>...])
New in version 3.19.
Same as CHMOD, but change the permissions of files and directories present in the <directories>...
recursively.
Path Conversion
file(REAL_PATH <path> <out-var> [BASE_DIRECTORY <dir>] [EXPAND_TILDE])
New in version 3.19.
Compute the absolute path to an existing file or directory with symlinks resolved.
BASE_DIRECTORY <dir>
If the provided <path> is a relative path, it is evaluated relative to the given base directory
<dir>. If no base directory is provided, the default base directory will be
CMAKE_CURRENT_SOURCE_DIR.
EXPAND_TILDE
New in version 3.21.
If the <path> is ~ or starts with ~/, the ~ is replaced by the user's home directory. The path to
the home directory is obtained from environment variables. On Windows, the USERPROFILE
environment variable is used, falling back to the HOME environment variable if USERPROFILE is not
defined. On all other platforms, only HOME is used.
file(RELATIVE_PATH <variable> <directory> <file>)
Compute the relative path from a <directory> to a <file> and store it in the <variable>.
file(TO_CMAKE_PATH "<path>" <variable>)
file(TO_NATIVE_PATH "<path>" <variable>)
The TO_CMAKE_PATH mode converts a native <path> into a cmake-style path with forward-slashes (/). The
input can be a single path or a system search path like $ENV{PATH}. A search path will be converted to a
cmake-style list separated by ; characters.
The TO_NATIVE_PATH mode converts a cmake-style <path> into a native path with platform-specific slashes
(\ on Windows hosts and / elsewhere).
Always use double quotes around the <path> to be sure it is treated as a single argument to this command.
Transfer
file(DOWNLOAD <url> [<file>] [<options>...])
file(UPLOAD <file> <url> [<options>...])
The DOWNLOAD subcommand downloads the given <url> to a local <file>. The UPLOAD mode uploads a local
<file> to a given <url>.
New in version 3.19: If <file> is not specified for file(DOWNLOAD), the file is not saved. This can be
useful if you want to know if a file can be downloaded (for example, to check that it exists) without
actually saving it anywhere.
Options to both DOWNLOAD and UPLOAD are:
INACTIVITY_TIMEOUT <seconds>
Terminate the operation after a period of inactivity.
LOG <variable>
Store a human-readable log of the operation in a variable.
SHOW_PROGRESS
Print progress information as status messages until the operation is complete.
STATUS <variable>
Store the resulting status of the operation in a variable. The status is a ; separated list of
length 2. The first element is the numeric return value for the operation, and the second element
is a string value for the error. A 0 numeric error means no error in the operation.
TIMEOUT <seconds>
Terminate the operation after a given total time has elapsed.
USERPWD <username>:<password>
New in version 3.7.
Set username and password for operation.
HTTPHEADER <HTTP-header>
New in version 3.7.
HTTP header for 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 variable will be used instead. Valid levels are:
IGNORED
The .netrc file is ignored. This is the default.
OPTIONAL
The .netrc file is optional, and information in the URL is preferred. The file will be
scanned to find which ever information is not specified in the URL.
REQUIRED
The .netrc file is required, and information in the URL is ignored.
NETRC_FILE <file>
New in version 3.11.
Specify an alternative .netrc file to the one in your home directory, if the NETRC level is
OPTIONAL or REQUIRED. If this option is not specified, the value of the CMAKE_NETRC_FILE variable
will be used instead.
TLS_VERIFY <ON|OFF>
Specify whether to verify the server certificate for https:// URLs. The default is to not verify.
If this option is not specified, the value of the CMAKE_TLS_VERIFY variable will be used instead.
New in version 3.18: Added support to file(UPLOAD).
TLS_CAINFO <file>
Specify a custom Certificate Authority file for https:// URLs. If this option is not specified,
the value of the CMAKE_TLS_CAINFO variable will be used instead.
New in version 3.18: Added support to file(UPLOAD).
For https:// URLs CMake must be built with OpenSSL support. TLS/SSL certificates are not checked by
default. Set TLS_VERIFY to ON to check certificates.
Additional options to DOWNLOAD are:
EXPECTED_HASH ALGO=<value>
Verify that the downloaded content hash matches the expected value, where ALGO is one of the
algorithms supported by file(<HASH>). If it does not match, the operation fails with an error. It is
an error to specify this 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>.
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 specified 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 instances sharing some modifiable resources. Similar logic applied to
DIRECTORY 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 directories, wildcards are not supported.
Use the FORMAT option to specify the archive format. Supported values for <format> are 7zip, gnutar,
pax, paxr, raw and zip. If FORMAT is not given, the default format is paxr.
Some archive formats allow the type of compression to be specified. The 7zip and zip archive formats
already imply a specific type of compression. The other formats use no compression by default, but can
be directed to do so with the COMPRESSION option. Valid values for <compression> are None, BZip2, GZip,
XZ, and Zstd.
New in version 3.19: The compression level can be specified with the COMPRESSION_LEVEL option. The
<compression-level> should be between 0-9, with the default being 0. The COMPRESSION option must be
present when COMPRESSION_LEVEL is given.
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])
New in version 3.18.
Extracts or lists the content of the specified <archive>.
The directory where the content of the archive will be extracted to can be specified using the
DESTINATION option. If the directory does not exist, it will be created. If DESTINATION is not given,
the current binary directory will be used.
If required, you may select which files and directories to list or extract from the archive using the
specified <patterns>. Wildcards are supported. If the PATTERNS option is not given, the entire archive
will be listed or extracted.
LIST_ONLY will list the files in the archive rather than extract them.
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]... ]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[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]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH]
)
This command is used to find a full path to named file. A cache entry, or a normal variable if NO_CACHE
is specified, named by <VAR> is created to store the result of this command. If the full path to a file
is found the result is stored in the variable and the search will not be repeated unless the variable is
cleared. If nothing is found, the result will be <VAR>-NOTFOUND.
Options include:
NAMES Specify one or more possible names for the full path to a file.
When using this to specify names with and without a version suffix, we recommend specifying the
unversioned name first so that locally-built packages can be found before those provided by
distributions.
HINTS, PATHS
Specify directories to search in addition to the default locations. The ENV var sub-option reads
paths from a system environment variable.
PATH_SUFFIXES
Specify additional subdirectories to check below each directory location otherwise considered.
DOC Specify the documentation string for the <VAR> cache entry.
NO_CACHE
New in version 3.21.
The result of the search will be stored in a normal variable rather than a cache entry.
NOTE:
If the variable is already set before the call (as a normal or cache variable) then the search
will not occur.
WARNING:
This option should be used with caution because it can greatly increase the cost of repeated
configure steps.
REQUIRED
New in version 3.18.
Stop processing with an error message if nothing is found, otherwise the search will be attempted
again the next time find_file is invoked with the same variable.
If NO_DEFAULT_PATH is specified, then no additional paths are added to the search. If NO_DEFAULT_PATH is
not specified, the search process is as follows:
1. 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 <CurrentPackage>_ROOT,
ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT, ENV{<ParentPackage>_ROOT}, etc. This can be skipped
if NO_PACKAGE_ROOT_PATH is passed or by setting the CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE. 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. This 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.
New in version 3.16: Added CMAKE_FIND_USE_<CATEGORY>_PATH variables to globally disable various search
locations.
On macOS the CMAKE_FIND_FRAMEWORK and CMAKE_FIND_APPBUNDLE variables determine the order of preference
between Apple-style and unix-style package components.
The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other
search directories. This effectively "re-roots" the entire search under given locations. Paths which
are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is
always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting
CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.
These variables are especially useful when cross-compiling to point to the root directory of the target
environment and CMake will search there too. By default at first the directories listed in
CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted
directories will be searched. The default behavior can be adjusted by setting
CMAKE_FIND_ROOT_PATH_MODE_INCLUDE. This behavior can be manually overridden on a per-call basis using
options:
CMAKE_FIND_ROOT_PATH_BOTH
Search in the order described above.
NO_CMAKE_FIND_ROOT_PATH
Do not use the CMAKE_FIND_ROOT_PATH variable.
ONLY_CMAKE_FIND_ROOT_PATH
Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.
The default search order is designed to be most-specific to least-specific for common use cases.
Projects may override the order by simply calling the command multiple times and using the NO_* options:
find_file (<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
find_file (<VAR> NAMES name)
Once one of the calls succeeds the result variable will be set and stored in the cache so that no call
will search again.
find_library
A short-hand signature is:
find_library (<VAR> name1 [path1 path2 ...])
The general signature is:
find_library (
<VAR>
name | NAMES name1 [name2 ...] [NAMES_PER_DIR]
[HINTS [path | ENV var]... ]
[PATHS [path | ENV var]... ]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[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]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH]
)
This command is used to find a library. A cache entry, or a normal variable if NO_CACHE is specified,
named by <VAR> is created to store the result of this command. If the library is found the result is
stored in the variable and the search will not be repeated unless the variable is cleared. If nothing is
found, the result will be <VAR>-NOTFOUND.
Options include:
NAMES Specify one or more possible names for the library.
When using this to specify names with and without a version suffix, we recommend specifying the
unversioned name first so that locally-built packages can be found before those provided by
distributions.
HINTS, PATHS
Specify directories to search in addition to the default locations. The ENV var sub-option reads
paths from a system environment variable.
PATH_SUFFIXES
Specify additional subdirectories to check below each directory location otherwise considered.
DOC Specify the documentation string for the <VAR> cache entry.
NO_CACHE
New in version 3.21.
The result of the search will be stored in a normal variable rather than a cache entry.
NOTE:
If the variable is already set before the call (as a normal or cache variable) then the search
will not occur.
WARNING:
This option should be used with caution because it can greatly increase the cost of repeated
configure steps.
REQUIRED
New in version 3.18.
Stop processing with an error message if nothing is found, otherwise the search will be attempted
again the next time find_library is invoked with the same variable.
If NO_DEFAULT_PATH is specified, then no additional paths are added to the search. If NO_DEFAULT_PATH is
not specified, the search process is as follows:
1. 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 <CurrentPackage>_ROOT,
ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT, ENV{<ParentPackage>_ROOT}, etc. This can be skipped
if NO_PACKAGE_ROOT_PATH is passed or by setting the CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE. 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 <prefix>/[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. This 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.
New in version 3.16: Added CMAKE_FIND_USE_<CATEGORY>_PATH variables to globally disable various search
locations.
On macOS the CMAKE_FIND_FRAMEWORK and CMAKE_FIND_APPBUNDLE variables determine the order of preference
between Apple-style and unix-style package components.
The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other
search directories. This effectively "re-roots" the entire search under given locations. Paths which
are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is
always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting
CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.
These variables are especially useful when cross-compiling to point to the root directory of the target
environment and CMake will search there too. By default at first the directories listed in
CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted
directories will be searched. The default behavior can be adjusted by setting
CMAKE_FIND_ROOT_PATH_MODE_LIBRARY. This behavior can be manually overridden on a per-call basis using
options:
CMAKE_FIND_ROOT_PATH_BOTH
Search in the order described above.
NO_CMAKE_FIND_ROOT_PATH
Do not use the CMAKE_FIND_ROOT_PATH variable.
ONLY_CMAKE_FIND_ROOT_PATH
Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.
The default search order is designed to be most-specific to least-specific for common use cases.
Projects may override the order by simply calling the command multiple times and using the NO_* options:
find_library (<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
find_library (<VAR> NAMES name)
Once one of the calls succeeds the result variable will be set and stored in the cache so that no call
will search again.
When more than one value is given to the NAMES option this command by default will consider one name at a
time and search every directory for it. The NAMES_PER_DIR option tells this command to consider one
directory at a time and search for all names in it.
Each library name given to the NAMES option is first considered as a library file name and then
considered with platform-specific prefixes (e.g. lib) and suffixes (e.g. .so). Therefore one may specify
library file names such as libfoo.a directly. This can be used to locate static libraries on UNIX-like
systems.
If the library found is a framework, then <VAR> will be set to the full path to the framework
<fullPath>/A.framework. When a full path to a framework is used as a library, CMake will use a
-framework A, and a -F<fullPath> to link the framework to the target.
If the CMAKE_FIND_LIBRARY_CUSTOM_LIB_SUFFIX variable is set all search paths will be tested as normal,
with the suffix appended, and with all matches of lib/ replaced with
lib${CMAKE_FIND_LIBRARY_CUSTOM_LIB_SUFFIX}/. This variable overrides the FIND_LIBRARY_USE_LIB32_PATHS,
FIND_LIBRARY_USE_LIBX32_PATHS, and FIND_LIBRARY_USE_LIB64_PATHS global properties.
If the FIND_LIBRARY_USE_LIB32_PATHS global property is set all search paths will be tested as normal,
with 32/ appended, and with all matches of lib/ replaced with lib32/. This property is automatically set
for the platforms that are known to need it if at least one of the languages supported by the project()
command is enabled.
If the FIND_LIBRARY_USE_LIBX32_PATHS global property is set all search paths will be tested as normal,
with x32/ appended, and with all matches of lib/ replaced with libx32/. This property is automatically
set for the platforms that are known to need it if at least one of the languages supported by the
project() command is enabled.
If the FIND_LIBRARY_USE_LIB64_PATHS global property is set all search paths will be tested as normal,
with 64/ appended, and with all matches of lib/ replaced with lib64/. This property is automatically set
for the platforms that are known to need it if at least one of the languages supported by the project()
command is enabled.
find_package
Find a package (usually provided by something external to the project), and load its package-specific
details.
Search Modes
The command has two very distinct ways of conducting the search:
Module mode
In this mode, CMake searches for a file called Find<PackageName>.cmake, looking first in the
locations listed in the CMAKE_MODULE_PATH, then among the Find Modules provided by the CMake
installation. If the file is found, it is read and processed by CMake. It is responsible for
finding the package, checking the version, and producing any needed messages. Some Find modules
provide limited or no support for versioning; check the Find module's documentation.
The Find<PackageName>.cmake file is not typically provided by the package itself. Rather, it is
normally provided by something external to the package, such as the operating system, CMake
itself, or even the project from which the find_package() command was called. Being externally
provided, Find Modules tend to be heuristic in nature and are susceptible to becoming out-of-date.
They typically search for certain libraries, files and other package artifacts.
Module mode is only supported by the basic command signature.
Config mode
In this mode, CMake searches for a file called <lowercasePackageName>-config.cmake or
<PackageName>Config.cmake. It will also look for <lowercasePackageName>-config-version.cmake or
<PackageName>ConfigVersion.cmake if version details were specified (see Config Mode Version
Selection for an explanation of how these separate version files are used).
In config mode, the command can be given a list of names to search for as package names. The
locations where CMake searches for the config and version files is considerably more complicated
than for Module mode (see Config Mode Search Procedure).
The config and version files are typically installed as part of the package, so they tend to be
more reliable than Find modules. They usually contain direct knowledge of the package contents,
so no searching or heuristics are needed within the config or version files themselves.
Config mode is supported by both the basic and full command signatures.
The command arguments determine which of the above modes is used. When the basic signature is used, the
command searches in Module mode first. If the package is not found, the search falls back to Config
mode. A user may set the CMAKE_FIND_PACKAGE_PREFER_CONFIG variable to true to reverse the priority and
direct CMake to search using Config mode first before falling back to Module mode. The basic signature
can also be forced to use only Module mode with a MODULE keyword. If the full signature is used, the
command only searches in Config mode.
Where possible, user code should generally look for packages using the basic signature, since that allows
the package to be found with either 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...]
[NO_POLICY_SCOPE])
The basic signature is supported by both Module and Config modes. The MODULE keyword implies that only
Module mode can be used to find the package, with no fallback to Config mode.
Regardless of the mode used, a <PackageName>_FOUND variable will be set to indicate whether the package
was found. When the package is found, package-specific information may be provided through other
variables and Imported Targets documented by the package itself. The QUIET option disables informational
messages, including those indicating that the package cannot be found if it is not REQUIRED. The
REQUIRED option stops processing with an error message if the package cannot be found.
A package-specific list of required components may be listed after the COMPONENTS keyword. If any of
these components are not able to be satisfied, the package overall is considered to be not found. If the
REQUIRED option is also present, this is treated as a fatal error, otherwise execution still continues.
As a form of shorthand, if the REQUIRED option is present, the COMPONENTS keyword can be omitted and the
required components can be listed directly after REQUIRED.
Additional optional components may be listed after OPTIONAL_COMPONENTS. If these cannot be satisfied,
the package overall can still be considered found, as long as all required components are satisfied.
The set of available components and their meaning are defined by the target package. Formally, it is up
to the target package how to interpret the component information given to it, but it should follow the
expectations stated above. For calls where no components are specified, there is no single expected
behavior and target packages should clearly define what occurs in such cases. Common arrangements
include assuming it should find all components, no components or some well-defined subset of the
available components.
The [version] argument requests a version with which the package found should be compatible. There are
two possible forms in which it may be specified:
• A single version with the format major[.minor[.patch[.tweak]]], where each component is a numeric
value.
• A version range with the format versionMin...[<]versionMax where versionMin and versionMax have the
same format and constraints on components being integers as the single version. By default, both
end points are included. By specifying <, the upper end point will be excluded. Version ranges are
only supported with CMake 3.19 or later.
The EXACT option requests that the version be matched exactly. This option is incompatible with the
specification of a version range.
If no [version] and/or component list is given to a recursive invocation inside a find-module, the
corresponding arguments are forwarded automatically from the outer call (including the EXACT flag for
[version]). Version support is currently provided only on a package-by-package basis (see the Version
Selection section below). When a version range is specified but the package is only designed to expect a
single version, the package will ignore the upper end point of the range and only take the single version
at the lower end of the range into account.
See the cmake_policy() command documentation for discussion of the NO_POLICY_SCOPE option.
Full Signature
find_package(<PackageName> [version] [EXACT] [QUIET]
[REQUIRED] [[COMPONENTS] [components...]]
[OPTIONAL_COMPONENTS components...]
[CONFIG|NO_MODULE]
[NO_POLICY_SCOPE]
[NAMES name1 [name2 ...]]
[CONFIGS config1 [config2 ...]]
[HINTS path1 [path2 ... ]]
[PATHS path1 [path2 ... ]]
[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_SYSTEM_PACKAGE_REGISTRY]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH])
The CONFIG option, the synonymous NO_MODULE option, or the use of options not specified in the basic
signature all enforce pure Config mode. In pure Config mode, the command skips Module mode search and
proceeds at once with Config mode search.
Config mode search attempts to locate a configuration file provided by the package to be found. A cache
entry called <PackageName>_DIR is created to hold the directory containing the file. By default the
command searches for a package with the name <PackageName>. If the NAMES option is given the names
following it are used instead of <PackageName>. The command searches for a file called
<PackageName>Config.cmake or <lowercasePackageName>-config.cmake for each name specified. A replacement
set of possible configuration file names may be given using the CONFIGS option. The Config Mode Search
Procedure is specified below. Once found, any version constraint is checked, and if satisfied, the
configuration file is read and processed by CMake. Since the file is provided by the package it already
knows the location of package contents. The full path to the configuration file is stored in the cmake
variable <PackageName>_CONFIG.
All configuration files which have been considered by CMake while searching for the package with an
appropriate version are stored in the <PackageName>_CONSIDERED_CONFIGS variable, and the associated
versions in the <PackageName>_CONSIDERED_VERSIONS variable.
If the package configuration file cannot be found CMake will generate an error describing the problem
unless the QUIET argument is specified. If REQUIRED is specified and the package is not found a fatal
error is generated and the configure step stops executing. If <PackageName>_DIR has been set to a
directory not containing a configuration file CMake will ignore it and search from scratch.
Package maintainers providing CMake package configuration files are encouraged to name and install them
such that the Config Mode Search Procedure outlined below will find them without requiring use of
additional options.
Config Mode Search Procedure
NOTE:
When Config mode is used, this search procedure is applied regardless of whether the full or basic
signature was given.
CMake constructs a set of possible installation prefixes for the package. Under each prefix several
directories are searched for a configuration file. The tables below show the directories searched. Each
entry is meant for installation trees following Windows (W), UNIX (U), or Apple (A) conventions:
<prefix>/ (W)
<prefix>/(cmake|CMake)/ (W)
<prefix>/<name>*/ (W)
<prefix>/<name>*/(cmake|CMake)/ (W)
<prefix>/(lib/<arch>|lib*|share)/cmake/<name>*/ (U)
<prefix>/(lib/<arch>|lib*|share)/<name>*/ (U)
<prefix>/(lib/<arch>|lib*|share)/<name>*/(cmake|CMake)/ (U)
<prefix>/<name>*/(lib/<arch>|lib*|share)/cmake/<name>*/ (W/U)
<prefix>/<name>*/(lib/<arch>|lib*|share)/<name>*/ (W/U)
<prefix>/<name>*/(lib/<arch>|lib*|share)/<name>*/(cmake|CMake)/ (W/U)
On systems supporting macOS FRAMEWORK and BUNDLE, the following directories are searched for Frameworks
or Application Bundles containing a configuration file:
<prefix>/<name>.framework/Resources/ (A)
<prefix>/<name>.framework/Resources/CMake/ (A)
<prefix>/<name>.framework/Versions/*/Resources/ (A)
<prefix>/<name>.framework/Versions/*/Resources/CMake/ (A)
<prefix>/<name>.app/Contents/Resources/ (A)
<prefix>/<name>.app/Contents/Resources/CMake/ (A)
In all cases the <name> is treated as case-insensitive and corresponds to any of the names specified
(<PackageName> or names given by NAMES).
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.
If PATH_SUFFIXES is specified, the suffixes are appended to each (W) or (U) directory entry one-by-one.
This set of directories is intended to work in cooperation with projects that provide configuration files
in their installation trees. Directories above marked with (W) are intended for installations on Windows
where the prefix may point at the top of an application's installation directory. Those marked with (U)
are intended for installations on UNIX platforms where the prefix is shared by multiple packages. This
is merely a convention, so all (W) and (U) directories are still searched on all platforms. Directories
marked with (A) are intended for installations on Apple platforms. The CMAKE_FIND_FRAMEWORK and
CMAKE_FIND_APPBUNDLE variables determine the order of preference.
The set of installation prefixes is constructed using the following steps. If NO_DEFAULT_PATH is
specified all NO_* options are enabled.
1. New in version 3.12: Search paths specified in the <PackageName>_ROOT CMake variable and the
<PackageName>_ROOT environment 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 location of another item already found. Hard-coded guesses should be
specified with the PATHS option.
5. Search the standard system environment variables. This can be skipped if NO_SYSTEM_ENVIRONMENT_PATH
is passed or by setting the CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH to FALSE. Path entries ending in
/bin or /sbin are automatically converted to their parent directories:
• PATH
6. Search paths stored in the CMake User Package Registry. This can be skipped if
NO_CMAKE_PACKAGE_REGISTRY is passed or by setting the variable CMAKE_FIND_USE_PACKAGE_REGISTRY to
FALSE or the deprecated variable CMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY to TRUE.
See the cmake-packages(7) manual for details on the user package registry.
7. Search cmake variables defined in the Platform files for the current system. This can be skipped if
NO_CMAKE_SYSTEM_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_SYSTEM_PATH to FALSE:
• CMAKE_SYSTEM_PREFIX_PATH
• CMAKE_SYSTEM_FRAMEWORK_PATH
• CMAKE_SYSTEM_APPBUNDLE_PATH
The platform paths that these variables contain are locations that typically include installed
software. An example being /usr/local for UNIX based platforms.
8. Search paths stored in the CMake System Package Registry. This can be skipped if
NO_CMAKE_SYSTEM_PACKAGE_REGISTRY is passed or by setting the CMAKE_FIND_USE_SYSTEM_PACKAGE_REGISTRY
variable to FALSE or the deprecated variable CMAKE_FIND_PACKAGE_NO_SYSTEM_PACKAGE_REGISTRY to TRUE.
See the cmake-packages(7) manual for details on the system package registry.
9. Search paths specified by the PATHS option. These are typically hard-coded guesses.
New in version 3.16: Added the CMAKE_FIND_USE_<CATEGORY> variables to globally disable various search
locations.
The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other
search directories. This effectively "re-roots" the entire search under given locations. Paths which
are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is
always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting
CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.
These variables are especially useful when cross-compiling to point to the root directory of the target
environment and CMake will search there too. By default at first the directories listed in
CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted
directories will be searched. The default behavior can be adjusted by setting
CMAKE_FIND_ROOT_PATH_MODE_PACKAGE. This behavior can be manually overridden on a per-call basis using
options:
CMAKE_FIND_ROOT_PATH_BOTH
Search in the order described above.
NO_CMAKE_FIND_ROOT_PATH
Do not use the CMAKE_FIND_ROOT_PATH variable.
ONLY_CMAKE_FIND_ROOT_PATH
Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.
The default search order is designed to be most-specific to least-specific for common use cases.
Projects may override the order by simply calling the command multiple times and using the NO_* options:
find_package (<PackageName> PATHS paths... NO_DEFAULT_PATH)
find_package (<PackageName>)
Once one of the calls succeeds the result variable will be set and stored in the cache so that no call
will search again.
By default the value stored in the result variable will be the path at which the file is found. The
CMAKE_FIND_PACKAGE_RESOLVE_SYMLINKS variable may be set to TRUE before calling find_package in order to
resolve symbolic links and store the real path to the file.
Every non-REQUIRED find_package call can be disabled or made REQUIRED:
• Setting the CMAKE_DISABLE_FIND_PACKAGE_<PackageName> variable to TRUE disables the package.
• Setting the CMAKE_REQUIRE_FIND_PACKAGE_<PackageName> variable to TRUE makes the package REQUIRED.
Setting both variables to TRUE simultaneously is an error.
Config Mode Version Selection
NOTE:
When Config mode is used, this version selection process is applied regardless of whether the full or
basic signature was given.
When the [version] argument is given, Config mode will only find a version of the package that claims
compatibility with the requested version (see format specification). If the EXACT option is given, only a
version of the package claiming an exact match of the requested version may be found. CMake does not
establish any convention for the meaning of version numbers. Package version numbers are checked by
"version" files provided by the packages themselves. For a candidate package configuration file
<config-file>.cmake the corresponding version file is located next to it and named either
<config-file>-version.cmake or <config-file>Version.cmake. If no such version file is available then the
configuration file is assumed to not be compatible with any requested version. A basic version file
containing generic version matching code can be created using the CMakePackageConfigHelpers module. When
a version file is found it is loaded to check the requested version number. The version file is loaded
in a nested scope in which the following variables have been defined:
PACKAGE_FIND_NAME
The <PackageName>
PACKAGE_FIND_VERSION
Full requested version string
PACKAGE_FIND_VERSION_MAJOR
Major version if requested, else 0
PACKAGE_FIND_VERSION_MINOR
Minor version if requested, else 0
PACKAGE_FIND_VERSION_PATCH
Patch version if requested, else 0
PACKAGE_FIND_VERSION_TWEAK
Tweak version if requested, else 0
PACKAGE_FIND_VERSION_COUNT
Number of version components, 0 to 4
When a version range is specified, the above version variables will hold values based on the lower end of
the version range. This is to preserve compatibility with packages that have not been implemented to
expect version ranges. In addition, the version range will be described by the following variables:
PACKAGE_FIND_VERSION_RANGE
Full requested version range string
PACKAGE_FIND_VERSION_RANGE_MIN
This specifies whether the lower end point of the version range should be included or excluded.
Currently, the only supported value for this variable is INCLUDE.
PACKAGE_FIND_VERSION_RANGE_MAX
This specifies whether the upper end point of the version range should be included or excluded.
The supported values for this variable are INCLUDE and EXCLUDE.
PACKAGE_FIND_VERSION_MIN
Full requested version string of the lower end point of the range
PACKAGE_FIND_VERSION_MIN_MAJOR
Major version of the lower end point if requested, else 0
PACKAGE_FIND_VERSION_MIN_MINOR
Minor version of the lower end point if requested, else 0
PACKAGE_FIND_VERSION_MIN_PATCH
Patch version of the lower end point if requested, else 0
PACKAGE_FIND_VERSION_MIN_TWEAK
Tweak version of the lower end point if requested, else 0
PACKAGE_FIND_VERSION_MIN_COUNT
Number of version components of the lower end point, 0 to 4
PACKAGE_FIND_VERSION_MAX
Full requested version string of the upper end point of the range
PACKAGE_FIND_VERSION_MAX_MAJOR
Major version of the upper end point if requested, else 0
PACKAGE_FIND_VERSION_MAX_MINOR
Minor version of the upper end point if requested, else 0
PACKAGE_FIND_VERSION_MAX_PATCH
Patch version of the upper end point if requested, else 0
PACKAGE_FIND_VERSION_MAX_TWEAK
Tweak version of the upper end point if requested, else 0
PACKAGE_FIND_VERSION_MAX_COUNT
Number of version components of the upper end point, 0 to 4
Regardless of whether a single version or a version range is specified, the variable
PACKAGE_FIND_VERSION_COMPLETE will be defined and will hold the full requested version string as
specified.
The version file checks whether it satisfies the requested version and sets these variables:
PACKAGE_VERSION
Full provided version string
PACKAGE_VERSION_EXACT
True if version is exact match
PACKAGE_VERSION_COMPATIBLE
True if version is compatible
PACKAGE_VERSION_UNSUITABLE
True if unsuitable as any version
These variables are checked by the find_package command to determine whether the configuration file
provides an acceptable version. They are not available after the find_package call returns. If the
version is acceptable the following variables are set:
<PackageName>_VERSION
Full provided version string
<PackageName>_VERSION_MAJOR
Major version if provided, else 0
<PackageName>_VERSION_MINOR
Minor version if provided, else 0
<PackageName>_VERSION_PATCH
Patch version if provided, else 0
<PackageName>_VERSION_TWEAK
Tweak version if provided, else 0
<PackageName>_VERSION_COUNT
Number of version components, 0 to 4
and the corresponding package configuration file is loaded. When multiple package configuration files
are available whose version files claim compatibility with the version requested it is unspecified which
one is chosen: unless the variable CMAKE_FIND_PACKAGE_SORT_ORDER is set no attempt is made to choose a
highest or closest version number.
To control the order in which find_package checks for compatibility use the two variables
CMAKE_FIND_PACKAGE_SORT_ORDER and CMAKE_FIND_PACKAGE_SORT_DIRECTION. For instance in order to select the
highest version one can set
SET(CMAKE_FIND_PACKAGE_SORT_ORDER NATURAL)
SET(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)
before calling find_package.
Package File Interface Variables
When loading a find module or package configuration file find_package defines variables to provide
information about the call arguments (and restores their original state before returning):
CMAKE_FIND_PACKAGE_NAME
The <PackageName> which is searched for
<PackageName>_FIND_REQUIRED
True if REQUIRED option was given
<PackageName>_FIND_QUIETLY
True if QUIET option was given
<PackageName>_FIND_VERSION
Full requested version string
<PackageName>_FIND_VERSION_MAJOR
Major version if requested, else 0
<PackageName>_FIND_VERSION_MINOR
Minor version if requested, else 0
<PackageName>_FIND_VERSION_PATCH
Patch version if requested, else 0
<PackageName>_FIND_VERSION_TWEAK
Tweak version if requested, else 0
<PackageName>_FIND_VERSION_COUNT
Number of version components, 0 to 4
<PackageName>_FIND_VERSION_EXACT
True if EXACT option was given
<PackageName>_FIND_COMPONENTS
List of specified components (required and optional)
<PackageName>_FIND_REQUIRED_<c>
True if component <c> is required, false if component <c> is optional
When a version range is specified, the above version variables will hold values based on the lower end of
the version range. This is to preserve compatibility with packages that have not been implemented to
expect version ranges. In addition, the version range will be described by the following variables:
<PackageName>_FIND_VERSION_RANGE
Full requested version range string
<PackageName>_FIND_VERSION_RANGE_MIN
This specifies whether the lower end point of the version range is included or excluded.
Currently, INCLUDE is the only supported value.
<PackageName>_FIND_VERSION_RANGE_MAX
This specifies whether the upper end point of the version range is included or excluded. The
possible values for this variable are INCLUDE or EXCLUDE.
<PackageName>_FIND_VERSION_MIN
Full requested version string of the lower end point of the range
<PackageName>_FIND_VERSION_MIN_MAJOR
Major version of the lower end point if requested, else 0
<PackageName>_FIND_VERSION_MIN_MINOR
Minor version of the lower end point if requested, else 0
<PackageName>_FIND_VERSION_MIN_PATCH
Patch version of the lower end point if requested, else 0
<PackageName>_FIND_VERSION_MIN_TWEAK
Tweak version of the lower end point if requested, else 0
<PackageName>_FIND_VERSION_MIN_COUNT
Number of version components of the lower end point, 0 to 4
<PackageName>_FIND_VERSION_MAX
Full requested version string of the upper end point of the range
<PackageName>_FIND_VERSION_MAX_MAJOR
Major version of the upper end point if requested, else 0
<PackageName>_FIND_VERSION_MAX_MINOR
Minor version of the upper end point if requested, else 0
<PackageName>_FIND_VERSION_MAX_PATCH
Patch version of the upper end point if requested, else 0
<PackageName>_FIND_VERSION_MAX_TWEAK
Tweak version of the upper end point if requested, else 0
<PackageName>_FIND_VERSION_MAX_COUNT
Number of version components of the upper end point, 0 to 4
Regardless of whether a single version or a version range is specified, the variable
<PackageName>_FIND_VERSION_COMPLETE will be defined and will hold the full requested version string as
specified.
In Module mode the loaded find module is responsible to honor the request detailed by these variables;
see the find module for details. In Config mode find_package handles REQUIRED, QUIET, and [version]
options automatically but leaves it to the package configuration file to handle components in a way that
makes sense for the package. The package configuration file may set <PackageName>_FOUND to false to tell
find_package that component requirements are not satisfied.
find_path
A short-hand signature is:
find_path (<VAR> name1 [path1 path2 ...])
The general signature is:
find_path (
<VAR>
name | NAMES name1 [name2 ...]
[HINTS [path | ENV var]... ]
[PATHS [path | ENV var]... ]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[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]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH]
)
This command is used to find a directory containing the named file. A cache entry, or a normal variable
if NO_CACHE is specified, named by <VAR> is created to store the result of this command. If the file in
a directory is found the result is stored in the variable and the search will not be repeated unless the
variable is cleared. If nothing is found, the result will be <VAR>-NOTFOUND.
Options include:
NAMES Specify one or more possible names for the file in a directory.
When using this to specify names with and without a version suffix, we recommend specifying the
unversioned name first so that locally-built packages can be found before those provided by
distributions.
HINTS, PATHS
Specify directories to search in addition to the default locations. The ENV var sub-option reads
paths from a system environment variable.
PATH_SUFFIXES
Specify additional subdirectories to check below each directory location otherwise considered.
DOC Specify the documentation string for the <VAR> cache entry.
NO_CACHE
New in version 3.21.
The result of the search will be stored in a normal variable rather than a cache entry.
NOTE:
If the variable is already set before the call (as a normal or cache variable) then the search
will not occur.
WARNING:
This option should be used with caution because it can greatly increase the cost of repeated
configure steps.
REQUIRED
New in version 3.18.
Stop processing with an error message if nothing is found, otherwise the search will be attempted
again the next time find_path is invoked with the same variable.
If NO_DEFAULT_PATH is specified, then no additional paths are added to the search. If NO_DEFAULT_PATH is
not specified, the search process is as follows:
1. 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 <CurrentPackage>_ROOT,
ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT, ENV{<ParentPackage>_ROOT}, etc. This can be skipped
if NO_PACKAGE_ROOT_PATH is passed or by setting the CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE. 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. This 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.
New in version 3.16: Added CMAKE_FIND_USE_<CATEGORY>_PATH variables to globally disable various search
locations.
On macOS the CMAKE_FIND_FRAMEWORK and CMAKE_FIND_APPBUNDLE variables determine the order of preference
between Apple-style and unix-style package components.
The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other
search directories. This effectively "re-roots" the entire search under given locations. Paths which
are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is
always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting
CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.
These variables are especially useful when cross-compiling to point to the root directory of the target
environment and CMake will search there too. By default at first the directories listed in
CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted
directories will be searched. The default behavior can be adjusted by setting
CMAKE_FIND_ROOT_PATH_MODE_INCLUDE. This behavior can be manually overridden on a per-call basis using
options:
CMAKE_FIND_ROOT_PATH_BOTH
Search in the order described above.
NO_CMAKE_FIND_ROOT_PATH
Do not use the CMAKE_FIND_ROOT_PATH variable.
ONLY_CMAKE_FIND_ROOT_PATH
Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.
The default search order is designed to be most-specific to least-specific for common use cases.
Projects may override the order by simply calling the command multiple times and using the NO_* options:
find_path (<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
find_path (<VAR> NAMES name)
Once one of the calls succeeds the result variable will be set and stored in the cache so that no call
will search again.
When searching for frameworks, if the file is specified as A/b.h, then the framework search will look for
A.framework/Headers/b.h. If that is found the path will be set to the path to the framework. CMake will
convert this to the correct -F option to include the file.
find_program
A short-hand signature is:
find_program (<VAR> name1 [path1 path2 ...])
The general signature is:
find_program (
<VAR>
name | NAMES name1 [name2 ...] [NAMES_PER_DIR]
[HINTS [path | ENV var]... ]
[PATHS [path | ENV var]... ]
[PATH_SUFFIXES suffix1 [suffix2 ...]]
[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]
[CMAKE_FIND_ROOT_PATH_BOTH |
ONLY_CMAKE_FIND_ROOT_PATH |
NO_CMAKE_FIND_ROOT_PATH]
)
This command is used to find a program. A cache entry, or a normal variable if NO_CACHE is specified,
named by <VAR> is created to store the result of this command. If the program is found the result is
stored in the variable and the search will not be repeated unless the variable is cleared. If nothing is
found, the result will be <VAR>-NOTFOUND.
Options include:
NAMES Specify one or more possible names for the program.
When using this to specify names with and without a version suffix, we recommend specifying the
unversioned name first so that locally-built packages can be found before those provided by
distributions.
HINTS, PATHS
Specify directories to search in addition to the default locations. The ENV var sub-option reads
paths from a system environment variable.
PATH_SUFFIXES
Specify additional subdirectories to check below each directory location otherwise considered.
DOC Specify the documentation string for the <VAR> cache entry.
NO_CACHE
New in version 3.21.
The result of the search will be stored in a normal variable rather than a cache entry.
NOTE:
If the variable is already set before the call (as a normal or cache variable) then the search
will not occur.
WARNING:
This option should be used with caution because it can greatly increase the cost of repeated
configure steps.
REQUIRED
New in version 3.18.
Stop processing with an error message if nothing is found, otherwise the search will be attempted
again the next time find_program is invoked with the same variable.
If NO_DEFAULT_PATH is specified, then no additional paths are added to the search. If NO_DEFAULT_PATH is
not specified, the search process is as follows:
1. 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 <CurrentPackage>_ROOT,
ENV{<CurrentPackage>_ROOT}, <ParentPackage>_ROOT, ENV{<ParentPackage>_ROOT}, etc. This can be skipped
if NO_PACKAGE_ROOT_PATH is passed or by setting the CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE. 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. This 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.
New in version 3.16: Added CMAKE_FIND_USE_<CATEGORY>_PATH variables to globally disable various search
locations.
On macOS the CMAKE_FIND_FRAMEWORK and CMAKE_FIND_APPBUNDLE variables determine the order of preference
between Apple-style and unix-style package components.
The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other
search directories. This effectively "re-roots" the entire search under given locations. Paths which
are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is
always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.
The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting
CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.
These variables are especially useful when cross-compiling to point to the root directory of the target
environment and CMake will search there too. By default at first the directories listed in
CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted
directories will be searched. The default behavior can be adjusted by setting
CMAKE_FIND_ROOT_PATH_MODE_PROGRAM. This behavior can be manually overridden on a per-call basis using
options:
CMAKE_FIND_ROOT_PATH_BOTH
Search in the order described above.
NO_CMAKE_FIND_ROOT_PATH
Do not use the CMAKE_FIND_ROOT_PATH variable.
ONLY_CMAKE_FIND_ROOT_PATH
Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.
The default search order is designed to be most-specific to least-specific for common use cases.
Projects may override the order by simply calling the command multiple times and using the NO_* options:
find_program (<VAR> NAMES name PATHS paths... NO_DEFAULT_PATH)
find_program (<VAR> NAMES name)
Once one of the calls succeeds the result variable will be set and stored in the cache so that no call
will search again.
When more than one value is given to the NAMES option this command by default will consider one name at a
time and search every directory for it. The NAMES_PER_DIR option tells this command to consider one
directory at a time and search for all names in it.
foreach
Evaluate a group of commands for each value in a list.
foreach(<loop_var> <items>)
<commands>
endforeach()
where <items> is a list of items that are separated by semicolon or whitespace. All commands between
foreach and the matching endforeach are recorded without being invoked. Once the endforeach is
evaluated, the recorded list of commands is invoked once for each item in <items>. At the beginning of
each iteration the variable <loop_var> will be set to the value of the current item.
The scope of <loop_var> is restricted to the loop scope. See policy CMP0124 for details.
The commands break() and continue() provide means to escape from the normal control flow.
Per legacy, the endforeach() command admits an optional <loop_var> argument. If used, it must be a
verbatim repeat of the argument of the opening foreach command.
foreach(<loop_var> RANGE <stop>)
In this variant, foreach iterates over the numbers 0, 1, ... up to (and including) the nonnegative
integer <stop>.
foreach(<loop_var> RANGE <start> <stop> [<step>])
In this variant, foreach iterates over the numbers from <start> up to at most <stop> in steps of <step>.
If <step> is not specified, then the step size is 1. The three arguments <start> <stop> <step> must all
be nonnegative integers, and <stop> must not be smaller than <start>; otherwise you enter the danger zone
of undocumented behavior that may change in future releases.
foreach(<loop_var> IN [LISTS [<lists>]] [ITEMS [<items>]])
In this variant, <lists> is a whitespace or semicolon separated list of list-valued variables. The
foreach command iterates over each item in each given list. The <items> following the ITEMS keyword are
processed as in the first variant of the foreach command. The forms LISTS A and ITEMS ${A} are
equivalent.
The following example shows how the LISTS option is processed:
set(A 0;1)
set(B 2 3)
set(C "4 5")
set(D 6;7 8)
set(E "")
foreach(X IN LISTS A B C D E)
message(STATUS "X=${X}")
endforeach()
yields
-- X=0
-- X=1
-- X=2
-- X=3
-- X=4 5
-- X=6
-- X=7
-- X=8
foreach(<loop_var>... IN ZIP_LISTS <lists>)
New in version 3.17.
In this variant, <lists> is a whitespace or semicolon separated list of list-valued variables. The
foreach command iterates over each list simultaneously setting the iteration variables as follows:
• if the only loop_var given, then it sets a series of loop_var_N variables to the current item from the
corresponding list;
• if multiple variable names passed, their count should match the lists variables count;
• if any of the lists are shorter, the corresponding iteration variable is not defined for the current
iteration.
list(APPEND English one two three four)
list(APPEND Bahasa satu dua tiga)
foreach(num IN ZIP_LISTS English Bahasa)
message(STATUS "num_0=${num_0}, num_1=${num_1}")
endforeach()
foreach(en ba IN ZIP_LISTS English Bahasa)
message(STATUS "en=${en}, ba=${ba}")
endforeach()
yields
-- num_0=one, num_1=satu
-- num_0=two, num_1=dua
-- num_0=three, num_1=tiga
-- num_0=four, num_1=
-- en=one, ba=satu
-- en=two, ba=dua
-- en=three, ba=tiga
-- en=four, ba=
function
Start recording a function for later invocation as a command.
function(<name> [<arg1> ...])
<commands>
endfunction()
Defines a function named <name> that takes arguments named <arg1>, ... The <commands> in the function
definition are recorded; they are not executed until the function is invoked.
Per legacy, the endfunction() command admits an optional <name> argument. If used, it must be a verbatim
repeat of the argument of the opening function command.
A function opens a new scope: see set(var PARENT_SCOPE) for details.
See the cmake_policy() command documentation for the behavior of policies inside functions.
See the macro() command documentation for differences between CMake functions and macros.
Invocation
The function invocation is case-insensitive. A function defined as
function(foo)
<commands>
endfunction()
can be invoked through any of
foo()
Foo()
FOO()
cmake_language(CALL foo)
and so on. However, it is strongly recommended to stay with the case chosen in the function definition.
Typically functions use all-lowercase names.
New in version 3.18: The cmake_language(CALL ...) command can also be used to invoke the function.
Arguments
When the function is invoked, the recorded <commands> are first modified by replacing formal parameters
(${arg1}, ...) with the arguments passed, and then invoked as normal commands.
In addition to referencing the formal parameters you can reference the ARGC variable which will be set to
the number of arguments passed into the function as well as ARGV0, ARGV1, ARGV2, ... which will have the
actual values of the arguments passed in. This facilitates creating functions with optional arguments.
Furthermore, ARGV holds the list of all arguments given to the function and ARGN holds the list of
arguments past the last expected argument. Referencing to ARGV# arguments beyond ARGC have undefined
behavior. Checking that ARGC is greater than # is the only way to ensure that ARGV# was passed to the
function as an extra argument.
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) manual
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 retrieve the property value instead of
the current directory. Relative paths are treated as relative to the current source directory. CMake
must already know about the directory, either by having added it through a call to add_subdirectory() or
being the top level directory.
New in version 3.19: <dir> may reference a binary directory.
If the property is not defined for the nominated directory scope, an empty string is returned. In the
case of INHERITED properties, if the property is not found for the nominated directory scope, the search
will chain to a parent scope as described for the define_property() command.
get_directory_property(<variable> [DIRECTORY <dir>]
DEFINITION <var-name>)
Get a variable definition from a directory. This form is useful to get a variable definition from
another directory.
See also the more general get_property() command.
get_filename_component
Get a specific component of a full filename.
Changed in version 3.20: This command been superseded by cmake_path() command, except REALPATH now
offered by file(REAL_PATH) command and PROGRAM now available in separate_arguments(PROGRAM) 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 property. It must be one of the following:
GLOBAL Scope is unique and does not accept a name.
DIRECTORY
Scope defaults to the current directory but another directory (already processed by CMake) may be
named by the full or relative path <dir>. Relative paths are treated as relative to the current
source directory. See also the get_directory_property() command.
New in version 3.19: <dir> may reference a binary directory.
TARGET Scope must name one existing target. See also the get_target_property() command.
SOURCE Scope must name one source file. By default, the source file's property will be read from the
current source directory's scope.
New in version 3.18: Directory scope can be overridden with one of the following sub-options:
DIRECTORY <dir>
The source file property will be read from the <dir> directory's scope. CMake must already
know about the directory, either by having added it through a call to add_subdirectory() or
<dir> being the top level directory. Relative paths are treated as relative to the current
source directory.
New in version 3.19: <dir> may reference a binary directory.
TARGET_DIRECTORY <target>
The source file property will be read from the directory scope in which <target> was
created (<target> must therefore already exist).
See also the get_source_file_property() command.
INSTALL
New in version 3.1.
Scope must name one installed file path.
TEST Scope must name one existing test. See also the get_test_property() command.
CACHE Scope must name one cache entry.
VARIABLE
Scope is unique and does not accept a name.
The required PROPERTY option is immediately followed by the name of the property to get. If the property
is not set an empty value is returned, although some properties support inheriting from a parent scope if
defined to behave that way (see define_property()).
If the SET option is given the variable is set to a boolean value indicating whether the property has
been set. If the DEFINED option is given the variable is set to a boolean value indicating whether the
property has been defined such as with the define_property() command.
If BRIEF_DOCS or FULL_DOCS is given then the variable is set to a string containing documentation for the
requested property. If documentation is requested for a property that has not been defined NOTFOUND is
returned.
NOTE:
The GENERATED source file property may be globally visible. See its documentation for details.
if
Conditionally execute a group of commands.
Synopsis
if(<condition>)
<commands>
elseif(<condition>) # optional block, can be repeated
<commands>
else() # optional block
<commands>
endif()
Evaluates the condition argument of the if clause according to the Condition syntax described below. If
the result is true, then the commands in the if block are executed. Otherwise, optional elseif blocks
are processed in the same way. Finally, if no condition is true, commands in the optional else block are
executed.
Per legacy, the else() and endif() commands admit an optional <condition> argument. If used, it must be
a verbatim repeat of the argument of the opening if command.
Condition Syntax
The following syntax applies to the condition argument of the if, elseif and while() clauses.
Compound conditions are evaluated in the following order of precedence: Innermost parentheses are
evaluated first. Next come unary tests such as EXISTS, COMMAND, and DEFINED. Then 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, and MATCHES. Then the boolean operators in the order NOT, AND, and finally OR.
Basic Expressions
if(<constant>)
True if the constant is 1, ON, YES, TRUE, Y, or a non-zero number. False if the constant is 0,
OFF, NO, FALSE, N, IGNORE, NOTFOUND, the empty string, or ends in the suffix -NOTFOUND. Named
boolean constants are case-insensitive. If the argument is not one of these specific constants,
it is treated as a variable or string (see Variable Expansion further below) and one of the
following two forms applies.
if(<variable>)
True if given a variable that is defined to a value that is not a false constant. False
otherwise, including if the variable is undefined. Note that macro arguments are not variables.
Environment variables also cannot be tested this way, e.g. if(ENV{some_var}) will always evaluate
to false.
if(<string>)
A quoted string always evaluates to false unless:
• The string's value is one of the true constants, or
• Policy CMP0054 is not set to NEW and the string's value happens to be a variable name that is
affected by CMP0054's behavior.
Logic Operators
if(NOT <condition>)
True if the condition is not true.
if(<cond1> AND <cond2>)
True if both conditions would be considered true individually.
if(<cond1> OR <cond2>)
True if either condition would be considered true individually.
if((condition) AND (condition OR (condition)))
The conditions inside the parenthesis are evaluated first and then the remaining condition is
evaluated as in the other examples. Where there are nested parenthesis the innermost are
evaluated as part of evaluating the condition that contains them.
Existence Checks
if(COMMAND command-name)
True if the given name is a command, macro or function that can be invoked.
if(POLICY policy-id)
True if the given name is an existing policy (of the form CMP<NNNN>).
if(TARGET target-name)
True if the given name is an existing logical target name created by a call to the
add_executable(), add_library(), or add_custom_target() command that has already been invoked (in
any directory).
if(TEST test-name)
New in version 3.3: True if the given name is an existing test name created by the add_test()
command.
if(DEFINED <name>|CACHE{<name>}|ENV{<name>})
True if a variable, cache variable or environment variable with given <name> is defined. The value
of the variable does not matter. Note that macro arguments are not variables.
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-defined only for full paths.
if(IS_ABSOLUTE path)
True if the given path is an absolute path. Note the following special cases:
• An empty path evaluates to false.
• On Windows hosts, any path that begins with a drive letter and colon (e.g. C:), a forward slash
or a backslash will evaluate to true. This means a path like C:no\base\dir will evaluate to
true, even though the non-drive part of the path is relative.
• On non-Windows hosts, any path that begins with a tilde (~) evaluates to true.
Comparisons
if(<variable|string> MATCHES regex)
True if the given string or variable's value matches the given regular expression. See Regex
Specification for regex format.
New in version 3.9: () groups are captured in CMAKE_MATCH_<n> variables.
if(<variable|string> LESS <variable|string>)
True if the given string or variable's value 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 lexicographically less than the string or variable
on the right.
if(<variable|string> STRGREATER <variable|string>)
True if the given string or variable's value is lexicographically greater than the string or
variable on the right.
if(<variable|string> STREQUAL <variable|string>)
True if the given string or variable's value is lexicographically equal to the string or variable
on the right.
if(<variable|string> STRLESS_EQUAL <variable|string>)
New in version 3.7: True if the given string or variable's value is lexicographically less than or
equal to the string or variable on the right.
if(<variable|string> STRGREATER_EQUAL <variable|string>)
New in version 3.7: True if the given string or variable's value is lexicographically greater than
or equal to the string or variable on the right.
Version Comparisons
if(<variable|string> VERSION_LESS <variable|string>)
Component-wise integer version number comparison (version format is major[.minor[.patch[.tweak]]],
omitted components are treated as zero). Any non-integer version component or non-integer
trailing part of a version component effectively truncates the string at that point.
if(<variable|string> VERSION_GREATER <variable|string>)
Component-wise integer version number comparison (version format is major[.minor[.patch[.tweak]]],
omitted components are treated as zero). Any non-integer version component or non-integer
trailing part of a version component effectively truncates the string at that point.
if(<variable|string> VERSION_EQUAL <variable|string>)
Component-wise integer version number comparison (version format is major[.minor[.patch[.tweak]]],
omitted components are treated as zero). Any non-integer version component or non-integer
trailing part of a version component effectively truncates the string at that point.
if(<variable|string> VERSION_LESS_EQUAL <variable|string>)
New in version 3.7: Component-wise integer version number comparison (version format is
major[.minor[.patch[.tweak]]], omitted components are treated as zero). Any non-integer version
component or non-integer trailing part of a version component effectively truncates the string at
that point.
if(<variable|string> VERSION_GREATER_EQUAL <variable|string>)
New in version 3.7: Component-wise integer version number comparison (version format is
major[.minor[.patch[.tweak]]], omitted components are treated as zero). Any non-integer version
component or non-integer trailing part of a version component effectively truncates the string at
that point.
Variable Expansion
The if command was written very early in CMake's history, predating the ${} variable evaluation syntax,
and for convenience evaluates variables named by its arguments as shown in the above signatures. Note
that normal variable evaluation with ${} applies before the if command even receives the arguments.
Therefore code like
set(var1 OFF)
set(var2 "var1")
if(${var2})
appears to the if command as
if(var1)
and is evaluated according to the if(<variable>) case documented above. The result is OFF which is
false. However, if we remove the ${} from the example then the command sees
if(var2)
which is true because var2 is defined to var1 which is not a false constant.
Automatic evaluation applies in the other cases whenever the above-documented condition syntax accepts
<variable|string>:
• The left hand argument to MATCHES is first checked to see if it is a defined variable, if so the
variable's value is used, otherwise the original value is used.
• If the left hand argument to MATCHES is missing it returns false without error
• Both left and right hand arguments to LESS, GREATER, EQUAL, LESS_EQUAL, and GREATER_EQUAL, are
independently tested to see if they are defined variables, if so their defined values are used
otherwise the original value is used.
• Both left and right hand arguments to STRLESS, STRGREATER, STREQUAL, STRLESS_EQUAL, and
STRGREATER_EQUAL are independently tested to see if they are defined variables, if so their defined
values are used otherwise the original value is used.
• Both left and right hand arguments to VERSION_LESS, VERSION_GREATER, VERSION_EQUAL, VERSION_LESS_EQUAL,
and VERSION_GREATER_EQUAL are independently tested to see if they are defined variables, if so their
defined values are used otherwise the original value is used.
• The right hand argument to NOT is tested to see if it is a boolean constant, if so the value is used,
otherwise it is assumed to be a variable and it is dereferenced.
• The left and right hand arguments to AND and OR are independently tested to see if they are boolean
constants, if so they are used as such, otherwise they are assumed to be variables and are
dereferenced.
Changed in version 3.1: To prevent ambiguity, potential variable or keyword names can be specified in a
Quoted Argument or a Bracket Argument. A quoted or bracketed variable or keyword will be interpreted as
a string and not dereferenced or interpreted. See policy CMP0054.
There is no automatic evaluation for environment or cache Variable References. Their values must be
referenced as $ENV{<name>} or $CACHE{<name>} wherever the above-documented condition syntax accepts
<variable|string>.
include
Load and run CMake code from a file or module.
include(<file|module> [OPTIONAL] [RESULT_VARIABLE <var>]
[NO_POLICY_SCOPE])
Loads and runs CMake code from the file given. Variable reads and writes access the scope of the caller
(dynamic scoping). If OPTIONAL is present, then no error is raised if the file does not exist. If
RESULT_VARIABLE is given the variable <var> will be set to the full filename which has been included or
NOTFOUND if it failed.
If a module is specified instead of a file, the file with name <modulename>.cmake is searched first in
CMAKE_MODULE_PATH, then in the CMake module directory. There is one exception to this: if the file which
calls include() is located itself in the CMake builtin module directory, then first the CMake builtin
module directory is searched and CMAKE_MODULE_PATH afterwards. See also policy CMP0017.
See the cmake_policy() command documentation for discussion of the NO_POLICY_SCOPE option.
include_guard
New in version 3.10.
Provides an include guard for the file currently being processed by CMake.
include_guard([DIRECTORY|GLOBAL])
Sets up an include guard for the current CMake file (see the CMAKE_CURRENT_LIST_FILE variable
documentation).
CMake will end its processing of the current file at the location of the include_guard() command if the
current file has already been processed for the applicable scope (see below). This provides functionality
similar to the include guards commonly used in source headers or to the #pragma once directive. If the
current file has been processed previously for the applicable scope, the effect is as though return() had
been called. Do not call this command from inside a function being defined within the current file.
An optional argument specifying the scope of the guard may be provided. Possible values for the option
are:
DIRECTORY
The include guard applies within the current directory and below. The file will only be included
once within this directory scope, but may be included again by other files outside of this
directory (i.e. a parent directory or another directory not pulled in by add_subdirectory() or
include() from the current file or its children).
GLOBAL The include guard applies globally to the whole build. The current file will only be included once
regardless of the scope.
If no arguments given, include_guard has the same scope as a variable, meaning that the include guard
effect is isolated by the most recent function scope or current directory if no inner function scopes
exist. In this case the command behavior is the same as:
if(__CURRENT_FILE_VAR__)
return()
endif()
set(__CURRENT_FILE_VAR__ TRUE)
list
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 actually defined in a parent scope. To propagate the results of these
operations upwards, use set() with PARENT_SCOPE, set() with CACHE INTERNAL, or some other means of value
propagation.
NOTE:
A list in cmake is a ; separated group of strings. To create a list the set command can be used. For
example, set(var a b c d e) creates a list with a;b;c;d;e, and set(var "a b c d e") creates a string
or a list with one item in it. (Note 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
indexed from the end of the list, with -1 representing the last list element. Be careful when
counting with negative indices: they do not start from 0. -0 is equivalent to 0, the first list
element.
Reading
list(LENGTH <list> <output variable>)
Returns the list's length.
list(GET <list> <element index> [<element index> ...] <output variable>)
Returns the list of elements specified by indices from the list.
list(JOIN <list> <glue> <output variable>)
New in version 3.12.
Returns a string joining all list's elements using the glue string. To join multiple strings, which are
not part of a list, use 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 <begin>+<length> then the remaining elements of the list starting at
<begin> will be returned.
Search
list(FIND <list> <value> <output variable>)
Returns the index of the element specified in the list or -1 if it wasn't found.
Modification
list(APPEND <list> [<element> ...])
Appends elements to the list.
list(FILTER <list> <INCLUDE|EXCLUDE> REGEX <regular_expression>)
New in version 3.6.
Includes or removes items from the list that match the mode's pattern. In REGEX mode, items will be
matched against the given regular expression.
For more information on regular expressions look under string(REGEX).
list(INSERT <list> <element_index> <element> [<element> ...])
Inserts elements to the list to the specified location.
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.
list(REMOVE_ITEM <list> <value> [<value> ...])
Removes all instances of the given items from the list.
list(REMOVE_AT <list> <index> [<index> ...])
Removes items at given indices from the list.
list(REMOVE_DUPLICATES <list>)
Removes duplicated items in the list. The relative order of items is preserved, but if duplicates are
encountered, only the first instance is preserved.
list(TRANSFORM <list> <ACTION> [<SELECTOR>]
[OUTPUT_VARIABLE <output variable>])
New in version 3.12.
Transforms the list by applying an action to all or, by specifying a <SELECTOR>, to the selected elements
of the list, storing the result in-place or in the specified output variable.
NOTE:
The TRANSFORM sub-command does not change the number of elements in the list. If a <SELECTOR> is
specified, only some elements will be changed, the other ones will remain the same as before the
transformation.
<ACTION> specifies the action to apply to the elements of the list. The actions have exactly the same
semantics as sub-commands of the string() command. <ACTION> must be one of the following:
APPEND, PREPEND: Append, prepend specified value to each element of the list.
list(TRANSFORM <list> <APPEND|PREPEND> <value> ...)
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, <SELECTOR> must be one of the following:
AT: Specify a list of indexes.
list(TRANSFORM <list> <ACTION> AT <index> [<index> ...] ...)
FOR: Specify a range with, optionally, an increment used to iterate over the range.
list(TRANSFORM <list> <ACTION> FOR <start> <stop> [<step>] ...)
REGEX: Specify a regular expression. Only elements matching the regular expression will be transformed.
list(TRANSFORM <list> <ACTION> REGEX <regular_expression> ...)
Ordering
list(REVERSE <list>)
Reverses the contents of the list in-place.
list(SORT <list> [COMPARE <compare>] [CASE <case>] [ORDER <order>])
Sorts the list in-place alphabetically.
New in version 3.13: Added the COMPARE, CASE, and ORDER options.
New in version 3.18: Added the COMPARE NATURAL option.
Use the COMPARE keyword to select the comparison method for sorting. The <compare> option should be one
of:
• STRING: Sorts a list of strings alphabetically. This is the default behavior if the COMPARE option is
not given.
• FILE_BASENAME: Sorts a list of pathnames of files by their basenames.
• NATURAL: Sorts a list of strings using natural order (see strverscmp(3) manual), i.e. such that
contiguous digits are compared as whole numbers. For example: the following list 10.0 1.1 2.1 8.0 2.0
3.1 will be sorted as 1.1 2.0 2.1 3.1 8.0 10.0 if the NATURAL comparison is selected where it will be
sorted as 1.1 10.0 2.0 2.1 3.1 8.0 with the STRING comparison.
Use the CASE keyword to select a case sensitive or case insensitive sort mode. The <case> option should
be one of:
• SENSITIVE: List items are sorted in a case-sensitive manner. This is the default behavior if the CASE
option is not given.
• INSENSITIVE: List items are sorted case insensitively. The order of items which differ only by
upper/lowercase is not specified.
To control the sort order, the ORDER keyword can be given. The <order> option should be one of:
• ASCENDING: Sorts the list in ascending order. This is the default behavior when the ORDER option is
not given.
• DESCENDING: Sorts the list in descending order.
macro
Start recording a macro for later invocation as a command
macro(<name> [<arg1> ...])
<commands>
endmacro()
Defines a macro named <name> that takes arguments named <arg1>, ... Commands listed after macro, but
before the matching endmacro(), are not executed until the macro is invoked.
Per legacy, the endmacro() command admits an optional <name> argument. If used, it must be a verbatim
repeat of the argument of the opening macro command.
See the cmake_policy() command documentation for the behavior of policies inside macros.
See the Macro vs Function section below for differences between CMake macros and functions.
Invocation
The macro invocation is case-insensitive. A macro defined as
macro(foo)
<commands>
endmacro()
can be invoked through any of
foo()
Foo()
FOO()
cmake_language(CALL foo)
and so on. However, it is strongly recommended to stay with the case chosen in the macro definition.
Typically macros use all-lowercase names.
New in version 3.18: The cmake_language(CALL ...) command can also be used to invoke the macro.
Arguments
When a macro is invoked, the commands recorded in the macro are first modified by replacing formal
parameters (${arg1}, ...) with the arguments passed, and then invoked as normal commands.
In addition to referencing the formal parameters you can reference the values ${ARGC} which will be set
to the number of arguments passed into the function as well as ${ARGV0}, ${ARGV1}, ${ARGV2}, ... which
will have the actual values of the arguments passed in. This facilitates creating macros with optional
arguments.
Furthermore, ${ARGV} holds the list of all arguments given to the macro and ${ARGN} holds the list of
arguments past the last expected argument. Referencing to ${ARGV#} arguments beyond ${ARGC} have
undefined behavior. Checking that ${ARGC} is greater than # is the only way to ensure that ${ARGV#} was
passed to the function as an extra argument.
Macro vs Function
The macro command is very similar to the function() command. Nonetheless, there are a few important
differences.
In a function, ARGN, ARGC, ARGV and ARGV0, ARGV1, ... are true variables in the usual CMake sense. In a
macro, they are not, they are string replacements much like the C preprocessor would do with a macro.
This has a number of consequences, as explained in the Argument Caveats section below.
Another difference between macros and functions is the control flow. A function is executed by
transferring control from the calling statement to the function body. A macro is executed as if the
macro body were pasted in place of the calling statement. This has the consequence that a return() in a
macro body does not just terminate execution of the macro; rather, control is returned from the scope of
the macro call. To avoid confusion, it is recommended to avoid return() in macros altogether.
Unlike a function, the CMAKE_CURRENT_FUNCTION, CMAKE_CURRENT_FUNCTION_LIST_DIR,
CMAKE_CURRENT_FUNCTION_LIST_FILE, CMAKE_CURRENT_FUNCTION_LIST_LINE variables are not set for a macro.
Argument Caveats
Since ARGN, ARGC, ARGV, ARGV0 etc. are not variables, you will NOT be able to use commands like
if(ARGV1) # ARGV1 is not a variable
if(DEFINED ARGV2) # ARGV2 is not a variable
if(ARGC GREATER 2) # ARGC is not a variable
foreach(loop_var IN LISTS ARGN) # ARGN is not a variable
In the first case, you can use if(${ARGV1}). In the second and third case, the proper way to check if an
optional variable was passed to the macro is to use if(${ARGC} GREATER 2). In the last case, you can use
foreach(loop_var ${ARGN}) but this will skip empty arguments. If you need to include them, you can use
set(list_var "${ARGN}")
foreach(loop_var IN LISTS list_var)
Note that if you have a variable with the same name in the scope from which the macro is called, using
unreferenced names will use the existing variable instead of the arguments. For example:
macro(bar)
foreach(arg IN LISTS ARGN)
<commands>
endforeach()
endmacro()
function(foo)
bar(x y z)
endfunction()
foo(a b c)
Will loop over a;b;c and not over x;y;z as one might have expected. If you want true CMake variables
and/or better CMake scope control you should look at the function command.
mark_as_advanced
Mark cmake cached variables as advanced.
mark_as_advanced([CLEAR|FORCE] <var1> ...)
Sets the advanced/non-advanced state of the named cached variables.
An advanced variable will not be displayed in any of the cmake GUIs unless the show advanced option is
on. In script mode, the advanced/non-advanced state has no effect.
If the keyword CLEAR is given then advanced variables are changed back to unadvanced. If the keyword
FORCE is given then the variables are made advanced. If neither FORCE nor CLEAR is specified, new values
will be marked as advanced, but if a variable already has an advanced/non-advanced state, it will not be
changed.
Changed in version 3.17: Variables passed to this command which are not already in the cache are ignored.
See policy CMP0102.
math
Evaluate a mathematical expression.
math(EXPR <variable> "<expression>" [OUTPUT_FORMAT <format>])
Evaluates a mathematical <expression> and sets <variable> to the resulting value. The result of the
expression must be representable as a 64-bit signed integer.
The mathematical expression must be given as a string (i.e. enclosed in double quotation marks). An
example is "5 * (10 + 13)". Supported operators are +, -, *, /, %, |, &, ^, ~, <<, >>, and (...); they
have the same meaning as in C code.
New in version 3.13: Hexadecimal numbers are recognized when prefixed with 0x, as in C code.
New in version 3.13: The result is formatted according to the option OUTPUT_FORMAT, where <format> is one
of
HEXADECIMAL
Hexadecimal notation as in C code, i. e. starting with "0x".
DECIMAL
Decimal notation. Which is also used if no OUTPUT_FORMAT option is specified.
For example
math(EXPR value "100 * 0xA" OUTPUT_FORMAT DECIMAL) # value is set to "1000"
math(EXPR value "100 * 0xA" OUTPUT_FORMAT HEXADECIMAL) # value is set to "0x3e8"
message
Log a message.
Synopsis
General messages
message([<mode>] "message text" ...)
Reporting checks
message(<checkState> "message text" ...)
General messages
message([<mode>] "message text" ...)
Record the specified message text in the log. If more than one message string is given, they are
concatenated into a single message with no separator between the strings.
The optional <mode> keyword determines the type of message, which influences the way the message is
handled:
FATAL_ERROR
CMake Error, stop processing and generation.
SEND_ERROR
CMake Error, continue processing, but skip generation.
WARNING
CMake Warning, continue processing.
AUTHOR_WARNING
CMake Warning (dev), continue processing.
DEPRECATION
CMake Deprecation Error or Warning if variable CMAKE_ERROR_DEPRECATED or CMAKE_WARN_DEPRECATED is
enabled, respectively, else no message.
(none) or NOTICE
Important message printed to stderr to attract user's attention.
STATUS The main interesting messages that project users might be interested in. Ideally these should be
concise, no more than a single line, but still informative.
VERBOSE
Detailed informational messages intended for project users. These messages should provide
additional details that won't be of interest in most cases, but which may be useful to those
building the project when they want deeper insight into what's happening.
DEBUG Detailed informational messages intended for developers working on the project itself as opposed
to users who just want to build it. These messages will not typically be of interest to other
users building the project and will often be closely related to internal implementation details.
TRACE Fine-grained messages with very low-level implementation details. Messages using this log level
would normally only be temporary and would expect to be removed before releasing the project,
packaging up the files, etc.
New in version 3.15: Added the NOTICE, VERBOSE, DEBUG, and TRACE levels.
The CMake command-line tool displays STATUS to TRACE messages on stdout with the message preceded by two
hyphens and a space. All other message types are sent to stderr and are not prefixed with hyphens. The
CMake GUI displays all messages in its log area. The curses interface shows STATUS to TRACE messages one
at a time on a status line and other messages in an interactive pop-up box. The --log-level command-line
option to each of these tools can be used to control which messages will be shown.
New in version 3.17: To make a log level persist between CMake runs, the CMAKE_MESSAGE_LOG_LEVEL variable
can be set instead. Note that the command line option takes precedence over the cache variable.
New in version 3.16: Messages of log levels NOTICE and below will have each line preceded by the content
of the CMAKE_MESSAGE_INDENT variable (converted to a single string by concatenating its list items). For
STATUS to TRACE messages, this indenting content will be inserted after the hyphens.
New in version 3.17: Messages of log levels NOTICE and below can also have each line preceded with
context of the form [some.context.example]. The content between the square brackets is obtained by
converting the CMAKE_MESSAGE_CONTEXT list variable to a dot-separated string. The message context will
always appear before any indenting content but after any automatically added leading hyphens. By default,
message context is not shown, it has to be explicitly enabled by giving the cmake --log-context
command-line option or by setting the CMAKE_MESSAGE_CONTEXT_SHOW variable to true. See the
CMAKE_MESSAGE_CONTEXT documentation for usage examples.
CMake Warning and Error message text displays using a simple markup language. Non-indented text is
formatted in line-wrapped paragraphs delimited by newlines. Indented text is considered pre-formatted.
Reporting checks
New in version 3.17.
A common pattern in CMake output is a message indicating the start of some sort of check, followed by
another message reporting the result of that check. For example:
message(STATUS "Looking for someheader.h")
#... do the checks, set checkSuccess with the result
if(checkSuccess)
message(STATUS "Looking for someheader.h - found")
else()
message(STATUS "Looking for someheader.h - not found")
endif()
This can be more robustly and conveniently expressed using the CHECK_... keyword form of the message()
command:
message(<checkState> "message" ...)
where <checkState> must be one of the following:
CHECK_START
Record a concise message about the check about to be performed.
CHECK_PASS
Record a successful result for a check.
CHECK_FAIL
Record an unsuccessful result for a check.
When recording a check result, the command repeats the message from the most recently started check for
which no result has yet been reported, then some separator characters and then the message text provided
after the CHECK_PASS or CHECK_FAIL keyword. Check messages are always reported at STATUS log level.
Checks may be nested and every CHECK_START should have exactly one matching CHECK_PASS or CHECK_FAIL.
The CMAKE_MESSAGE_INDENT variable can also be used to add indenting to nested checks if desired. For
example:
message(CHECK_START "Finding my things")
list(APPEND CMAKE_MESSAGE_INDENT " ")
unset(missingComponents)
message(CHECK_START "Finding partA")
# ... do check, assume we find A
message(CHECK_PASS "found")
message(CHECK_START "Finding partB")
# ... do check, assume we don't find B
list(APPEND missingComponents B)
message(CHECK_FAIL "not found")
list(POP_BACK CMAKE_MESSAGE_INDENT)
if(missingComponents)
message(CHECK_FAIL "missing components: ${missingComponents}")
else()
message(CHECK_PASS "all components found")
endif()
Output from the above would appear something like the following:
-- Finding my things
-- Finding partA
-- Finding partA - found
-- Finding partB
-- Finding partB - not found
-- Finding my things - missing components: B
option
Provide an option that the user can optionally select.
option(<variable> "<help_text>" [value])
Provides an option for the user to select as ON or OFF. If no initial <value> is provided, OFF is used.
If <variable> is already set as a normal or cache variable, then the command does nothing (see policy
CMP0077).
If you have options that depend on the values of other options, see the module help for
CMakeDependentOption.
return
Return from a file, directory or function.
return()
Returns from a file, directory or function. When this command is encountered in an included file (via
include() or find_package()), it causes processing of the current file to stop and control is returned to
the including file. If it is encountered in a file which is not included by another file, e.g. a
CMakeLists.txt, deferred calls scheduled by cmake_language(DEFER) are invoked and control is returned to
the parent directory if there is one. If return is called in a function, control is returned to the
caller of the function.
Note that a macro, unlike a function, is expanded in place and therefore cannot handle return().
separate_arguments
Parse command-line arguments into a semicolon-separated list.
separate_arguments(<variable> <mode> [PROGRAM [SEPARATE_ARGS]] <args>)
Parses a space-separated string <args> into a list of items, and stores this list in semicolon-separated
standard form in <variable>.
This function is intended for parsing command-line arguments. The entire command line must be passed as
one string in the argument <args>.
The exact parsing rules depend on the operating system. They are specified by the <mode> argument which
must be one of the following keywords:
UNIX_COMMAND
Arguments are separated by unquoted whitespace. Both single-quote and double-quote pairs are
respected. A backslash escapes the next literal character (\" is "); there are no special escapes
(\n is just n).
WINDOWS_COMMAND
A Windows command-line is parsed using the same syntax the runtime library uses to construct argv
at startup. It separates arguments by whitespace that is not double-quoted. Backslashes are
literal unless they precede double-quotes. See the MSDN article Parsing C Command-Line Arguments
for details.
NATIVE_COMMAND
New in version 3.9.
Proceeds as in WINDOWS_COMMAND mode if the host system is Windows. Otherwise proceeds as in
UNIX_COMMAND mode.
PROGRAM
New in version 3.19.
The first item in <args> is assumed to be an executable and will be searched in the system search
path or left as a full path. If not found, <variable> will be empty. Otherwise, <variable> is a
list of 2 elements:
0. Absolute path of the program
1. Any command-line arguments present in <args> as a string
For example:
separate_arguments (out UNIX_COMMAND PROGRAM "cc -c main.c")
• First element of the list: /path/to/cc
• Second element of the list: " -c main.c"
SEPARATE_ARGS
When this sub-option of PROGRAM option is specified, command-line arguments will be split as well
and stored in <variable>.
For example:
separate_arguments (out UNIX_COMMAND PROGRAM SEPARATE_ARGS "cc -c main.c")
The contents of out will be: /path/to/cc;-c;main.c
separate_arguments(<var>)
Convert the value of <var> to a semi-colon separated list. All spaces are replaced with ';'. This helps
with generating command lines.
set
Set a normal, cache, or environment variable to a given value. See the cmake-language(7) variables
documentation for the scopes and interaction of normal variables and cache entries.
Signatures of this command that specify a <value>... placeholder expect zero or more arguments. Multiple
arguments will be joined as a semicolon-separated list to form the actual variable value to be set. 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 creates a new scope. This command will set the value of a variable into the
parent directory or calling function (whichever is applicable to the case at hand). The previous state of
the variable's value stays the same in the current scope (e.g., if it was undefined before, it is still
undefined and if it had a value, it is still that value).
Set Cache Entry
set(<variable> <value>... CACHE <type> <docstring> [FORCE])
Sets the given cache <variable> (cache entry). Since cache entries are meant to provide user-settable
values this does not overwrite existing cache entries by default. Use the FORCE option to overwrite
existing entries.
The <type> must be specified as one of:
BOOL Boolean ON/OFF value. cmake-gui(1) offers a checkbox.
FILEPATH
Path to a file on disk. cmake-gui(1) offers a file dialog.
PATH Path to a directory on disk. cmake-gui(1) offers a file dialog.
STRING A line of text. cmake-gui(1) offers a text field or a drop-down selection if the STRINGS cache
entry property is set.
INTERNAL
A line of text. cmake-gui(1) does not show internal entries. They may be used to store variables
persistently across runs. Use of this type implies FORCE.
The <docstring> must be specified as a line of text providing a quick summary of the option for
presentation to cmake-gui(1) users.
If the cache entry does not exist prior to the call or the FORCE option is given then the cache entry
will be set to the given value.
NOTE:
The content of the cache variable will not be directly accessible if a normal variable of the same
name already exists (see rules of variable evaluation). If policy CMP0126 is set to OLD, any normal
variable binding in the current scope will be removed.
It is possible for the cache entry to exist prior to the call but have no type set if it was created on
the cmake(1) command line by a user through the -D<var>=<value> option without specifying a type. In
this case the set command will add the type. Furthermore, if the <type> is PATH or FILEPATH and the
<value> provided on the command line is a relative path, then the set command will treat the path as
relative to the current working directory and convert it to an absolute path.
Set Environment Variable
set(ENV{<variable>} [<value>])
Sets an Environment Variable to the given value. Subsequent calls of $ENV{<variable>} will return this
new value.
This command affects only the current CMake process, not the process from which CMake was called, nor the
system environment at large, nor the environment of subsequent build or test processes.
If no argument is given after ENV{<variable>} or if <value> is an empty string, then this command will
clear any existing value of the environment variable.
Arguments after <value> are ignored. If extra arguments are found, then an author warning is issued.
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 Directory Properties 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() command.
New in version 3.19: <dir> may reference a binary directory.
TARGET Scope may name zero or more existing targets. See also the set_target_properties() command.
SOURCE Scope may name zero or more source files. By default, source file properties are only visible to
targets added in the same directory (CMakeLists.txt).
New in version 3.18: Visibility can be set in other directory scopes using one or both of the
following sub-options:
DIRECTORY <dirs>...
The source file property will be set in each of the <dirs> directories' scopes. CMake must
already know about each of these directories, either by having added them through a call to
add_subdirectory() or it being the top level source directory. Relative paths are treated
as relative to the current source directory.
New in version 3.19: <dirs> may reference a binary directory.
TARGET_DIRECTORY <targets>...
The source file property will be set in each of the directory scopes where any of the
specified <targets> were created (the <targets> must therefore already exist).
See also the set_source_files_properties() command.
INSTALL
New in version 3.1.
Scope may name zero or more installed file paths. These are made available to CPack to influence
deployment.
Both the property key and value may use generator expressions. Specific properties may apply to
installed files and/or directories.
Path components have to be separated by forward slashes, must be normalized and are case
sensitive.
To reference the installation prefix itself with a relative path use ..
Currently installed file properties are only defined for the WIX generator where the given paths
are relative to the installation prefix.
TEST Scope may name zero or more existing tests. See also the set_tests_properties() command.
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
existing property value as string, i.e. it results in a longer string and not a list of strings. When
using APPEND or APPEND_STRING with a property defined to support INHERITED behavior (see
define_property()), no inheriting occurs when finding the initial value to append to. If the property is
not already directly set in the nominated scope, the command will behave as though APPEND or
APPEND_STRING had not been given.
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 supplied <string>. If the REVERSE flag
was used, the command will search for the position of the last occurrence of the specified <substring>.
If the <substring> is not found, a position of -1 is returned.
The string(FIND) subcommand treats all strings as ASCII-only characters. The index stored in
<output_variable> will also be counted in bytes, so strings containing multi-byte characters may lead to
unexpected results.
string(REPLACE <match_string>
<replace_string> <output_variable>
<input> [<input>...])
Replace all occurrences of <match_string> in the <input> with <replace_string> and store the result in
the <output_variable>.
Search and Replace With Regular Expressions
string(REGEX MATCH <regular_expression>
<output_variable> <input> [<input>...])
Match the <regular_expression> once and store the match in the <output_variable>. All <input> arguments
are concatenated before matching. Regular expressions are specified in the subsection just below.
string(REGEX MATCHALL <regular_expression>
<output_variable> <input> [<input>...])
Match the <regular_expression> as many times as possible and store the matches in the <output_variable>
as a list. All <input> arguments are concatenated before matching.
string(REGEX REPLACE <regular_expression>
<replacement_expression> <output_variable>
<input> [<input>...])
Match the <regular_expression> as many times as possible and substitute the <replacement_expression> for
the match in the output. All <input> arguments are concatenated before matching.
The <replacement_expression> may refer to parenthesis-delimited subexpressions of the match using \1, \2,
..., \9. Note that two backslashes (\\1) are required in CMake code to get a backslash through argument
parsing.
Regex Specification
The following characters have special meaning in regular expressions:
^ Matches at beginning of input
$ Matches at end of input
. Matches any single character
\<char>
Matches the single character specified by <char>. Use this to match special regex characters,
e.g. \. for a literal . or \\ for a literal backslash \. Escaping a non-special character is
unnecessary but allowed, e.g. \a matches a.
[ ] Matches any character(s) inside the brackets
[^ ] Matches any character(s) not inside the brackets
- Inside brackets, specifies an inclusive range between characters on either side e.g. [a-f] is
[abcdef] To match a literal - using brackets, make it the first or the last character e.g. [+*/-]
matches basic mathematical operators.
* Matches preceding pattern zero or more times
+ Matches preceding pattern one or more times
? Matches preceding pattern zero or once only
| Matches a pattern on either side of the |
() Saves a matched subexpression, which can be referenced in the REGEX REPLACE operation.
New in version 3.9: All regular expression-related commands, including e.g. if(MATCHES), save
subgroup matches in the variables CMAKE_MATCH_<n> for <n> 0..9.
*, + and ? have higher precedence than concatenation. | has lower precedence than concatenation. This
means that the regular expression ^ab+d$ matches abbd but not ababd, and the regular expression ^(ab|cd)$
matches ab but not abd.
CMake language Escape Sequences such as \t, \r, \n, and \\ may be used to construct literal tabs,
carriage returns, newlines, and backslashes (respectively) to pass in a regex. For example:
• The quoted argument "[ \t\r\n]" specifies a regex that matches any single whitespace character.
• The quoted argument "[/\\]" specifies a regex that matches a single forward slash / or backslash \.
• The quoted argument "[A-Za-z0-9_]" specifies a regex that matches any single "word" character in the C
locale.
• The quoted argument "\\(\\a\\+b\\)" specifies a regex that matches the exact string (a+b). Each \\ is
parsed in a quoted argument as just \, so the regex itself is actually \(\a\+\b\). This can
alternatively be specified in a bracket argument without having to escape the backslashes, e.g.
[[\(\a\+\b\)]].
Manipulation
string(APPEND <string_variable> [<input>...])
New in version 3.4.
Append all the <input> arguments to the string.
string(PREPEND <string_variable> [<input>...])
New in version 3.10.
Prepend all the <input> arguments to the string.
string(CONCAT <output_variable> [<input>...])
Concatenate all the <input> arguments together and store the result in the named <output_variable>.
string(JOIN <glue> <output_variable> [<input>...])
New in version 3.12.
Join all the <input> arguments together using the <glue> string and store the result in the named
<output_variable>.
To join a list's elements, prefer to use the JOIN operator from the list() command. This allows for the
elements to have special characters like ; in them.
string(TOLOWER <string> <output_variable>)
Convert <string> to lower characters.
string(TOUPPER <string> <output_variable>)
Convert <string> to upper characters.
string(LENGTH <string> <output_variable>)
Store in an <output_variable> a given string's length in bytes. Note that this means if <string>
contains multi-byte characters, the result stored in <output_variable> will not be the number of
characters.
string(SUBSTRING <string> <begin> <length> <output_variable>)
Store in an <output_variable> a substring of a given <string>. If <length> is -1 the remainder of the
string starting at <begin> will be returned.
Changed in version 3.2: If <string> is shorter than <length> then the end of the string is used instead.
Previous versions of CMake reported an error in this case.
Both <begin> and <length> are counted in bytes, so care must be exercised if <string> could contain
multi-byte characters.
string(STRIP <string> <output_variable>)
Store in an <output_variable> a substring of a given <string> with leading and trailing spaces removed.
string(GENEX_STRIP <string> <output_variable>)
New in version 3.1.
Strip any generator expressions from the input <string> and store the result in the <output_variable>.
string(REPEAT <string> <count> <output_variable>)
New in version 3.15.
Produce the output string as the input <string> repeated <count> times.
Comparison
string(COMPARE LESS <string1> <string2> <output_variable>)
string(COMPARE GREATER <string1> <string2> <output_variable>)
string(COMPARE EQUAL <string1> <string2> <output_variable>)
string(COMPARE NOTEQUAL <string1> <string2> <output_variable>)
string(COMPARE LESS_EQUAL <string1> <string2> <output_variable>)
string(COMPARE GREATER_EQUAL <string1> <string2> <output_variable>)
Compare the strings and store true or false in the <output_variable>.
New in version 3.7: Added the LESS_EQUAL and GREATER_EQUAL options.
Hashing
string(<HASH> <output_variable> <input>)
Compute a cryptographic hash of the <input> string. The supported <HASH> algorithm names are:
MD5 Message-Digest Algorithm 5, RFC 1321.
SHA1 US Secure Hash Algorithm 1, RFC 3174.
SHA224 US Secure Hash Algorithms, RFC 4634.
SHA256 US Secure Hash Algorithms, RFC 4634.
SHA384 US Secure Hash Algorithms, RFC 4634.
SHA512 US Secure Hash Algorithms, RFC 4634.
SHA3_224
Keccak SHA-3.
SHA3_256
Keccak SHA-3.
SHA3_384
Keccak SHA-3.
SHA3_512
Keccak SHA-3.
New in version 3.8: Added the SHA3_* hash algorithms.
Generation
string(ASCII <number> [<number> ...] <output_variable>)
Convert all numbers into corresponding ASCII characters.
string(HEX <string> <output_variable>)
New in version 3.18.
Convert each byte in the input <string> to its hexadecimal representation and store the concatenated hex
digits in the <output_variable>. Letters in the output (a through f) are in lowercase.
string(CONFIGURE <string> <output_variable>
[@ONLY] [ESCAPE_QUOTES])
Transform a <string> like configure_file() transforms a file.
string(MAKE_C_IDENTIFIER <string> <output_variable>)
Convert each non-alphanumeric character in the input <string> to an underscore and store the result in
the <output_variable>. If the first character of the <string> is a digit, an underscore will also be
prepended to the result.
string(RANDOM [LENGTH <length>] [ALPHABET <alphabet>]
[RANDOM_SEED <seed>] <output_variable>)
Return a random string of given <length> consisting of characters from the given <alphabet>. Default
length is 5 characters and default alphabet is all numbers and upper and lower case letters. If an
integer RANDOM_SEED is given, its value will be used to seed the random number generator.
string(TIMESTAMP <output_variable> [<format_string>] [UTC])
Write a string representation of the current date and/or time to the <output_variable>.
If the command is unable to obtain a timestamp, the <output_variable> will be set to the empty string "".
The optional UTC flag requests the current date/time representation to be in Coordinated Universal Time
(UTC) rather than local time.
The optional <format_string> may contain the following format specifiers:
%% New in version 3.8.
A literal percent sign (%).
%d The day of the current month (01-31).
%H The hour on a 24-hour clock (00-23).
%I The hour on a 12-hour clock (01-12).
%j The day of the current year (001-366).
%m The month of the current year (01-12).
%b New in version 3.7.
Abbreviated month name (e.g. Oct).
%B New in version 3.10.
Full month name (e.g. October).
%M The minute of the current hour (00-59).
%s New in version 3.6.
Seconds since midnight (UTC) 1-Jan-1970 (UNIX time).
%S The second of the current minute. 60 represents a leap second. (00-60)
%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 representation
can be requested with the optional UPPER flag.
JSON
New in version 3.19.
Functionality for querying a JSON string.
NOTE:
In each of the following JSON-related subcommands, if the optional ERROR_VARIABLE argument is given,
errors will be reported in <error-variable> and the <out-var> will be set to
<member|index>-[<member|index>...]-NOTFOUND with the path elements up to the point where the error
occurred, or just NOTFOUND if there is no relevant path. If an error occurs but the ERROR_VARIABLE
option is not present, a fatal error message is generated. If no error occurs, the <error-variable>
will be set to NOTFOUND.
string(JSON <out-var> [ERROR_VARIABLE <error-variable>]
GET <json-string> <member|index> [<member|index> ...])
Get an element from <json-string> at the location given by the list of <member|index> arguments. Array
and object elements will be returned as a JSON string. Boolean elements will be returned as ON or OFF.
Null elements will be returned as an empty string. Number and string types will be returned as strings.
string(JSON <out-var> [ERROR_VARIABLE <error-variable>]
TYPE <json-string> <member|index> [<member|index> ...])
Get the type of an element in <json-string> at the location given by the list of <member|index>
arguments. The <out-var> will be set to one of NULL, NUMBER, STRING, BOOLEAN, ARRAY, or OBJECT.
string(JSON <out-var> [ERROR_VARIABLE <error-var>]
MEMBER <json-string>
[<member|index> ...] <index>)
Get the name of the <index>-th member in <json-string> at the location given by the list of
<member|index> arguments. Requires an element of object type.
string(JSON <out-var> [ERROR_VARIABLE <error-variable>]
LENGTH <json-string> <member|index> [<member|index> ...])
Get the length of an element in <json-string> at the location given by the list of <member|index>
arguments. Requires an element of array or object type.
string(JSON <out-var> [ERROR_VARIABLE <error-variable>]
REMOVE <json-string> <member|index> [<member|index> ...])
Remove an element from <json-string> at the location given by the list of <member|index> arguments. The
JSON string without the removed element will be stored in <out-var>.
string(JSON <out-var> [ERROR_VARIABLE <error-variable>]
SET <json-string> <member|index> [<member|index> ...] <value>)
Set an element in <json-string> at the location given by the list of <member|index> arguments to <value>.
The contents of <value> should be valid JSON.
string(JSON <out-var> [ERROR_VARIABLE <error-var>]
EQUAL <json-string1> <json-string2>)
Compare the two JSON objects given by <json-string1> and <json-string2> for equality. The contents of
<json-string1> and <json-string2> should be valid JSON. The <out-var> will be set to a true value if the
JSON objects are considered equal, or a false value otherwise.
unset
Unset a variable, cache variable, or environment variable.
Unset Normal Variable or Cache Entry
unset(<variable> [CACHE | PARENT_SCOPE])
Removes a normal variable from the current scope, causing it to become undefined. If CACHE is present,
then a cache variable is removed instead of a normal variable. Note that when evaluating Variable
References of the form ${VAR}, CMake first searches for a normal variable with that name. If no such
normal variable exists, CMake will then search for a cache entry with that name. Because of this
unsetting a normal variable can expose a cache variable that was previously hidden. To force a variable
reference of the form ${VAR} to return an empty string, use set(<variable> ""), which clears the normal
variable but leaves it defined.
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 message will be printed to inform about
the change.
If <command> is given, this command will be executed instead. The command will receive the following
arguments: COMMAND(<variable> <access> <value> <current_list_file> <stack>)
<variable>
Name of the variable being accessed.
<access>
One of READ_ACCESS, UNKNOWN_READ_ACCESS, MODIFIED_ACCESS, UNKNOWN_MODIFIED_ACCESS, or
REMOVED_ACCESS. The UNKNOWN_ values are only used when the variable has never been set. Once
set, they are never used again during the same CMake run, even if the variable is later unset.
<value>
The value of the variable. On a modification, this is the new (modified) value of the variable.
On removal, the value is empty.
<current_list_file>
Full path to the file doing the access.
<stack>
List of absolute paths of all files currently on the stack of file inclusion, with the bottom-most
file first and the currently processed file (that is, current_list_file) last.
Note that for some accesses such as list(APPEND), the watcher is executed twice, first with a read access
and then with a write one. Also note that an if(DEFINED) query on the variable does not register as an
access and the watcher is not executed.
Only non-cache variables can be watched using this command. Access to cache variables is never watched.
However, the existence of a cache variable var causes accesses to the non-cache variable var to not use
the UNKNOWN_ prefix, even if a non-cache variable var has never existed.
while
Evaluate a group of commands while a condition is true
while(<condition>)
<commands>
endwhile()
All commands between while and the matching endwhile() are recorded without being invoked. Once the
endwhile() is evaluated, the recorded list of commands is invoked as long as the <condition> is true.
The <condition> has the same syntax and is evaluated using the same logic as described at length for the
if() command.
The commands break() and continue() provide means to escape from the normal control flow.
Per legacy, the endwhile() command admits an optional <condition> argument. If used, it must be a
verbatim repeat of the argument of the opening while command.
PROJECT COMMANDS
These commands are available only in CMake projects.
add_compile_definitions
New in version 3.12.
Add preprocessor definitions to the compilation of source files.
add_compile_definitions(<definition> ...)
Adds preprocessor definitions to the compiler command line.
The preprocessor definitions are added to the COMPILE_DEFINITIONS directory property for the current
CMakeLists file. They are also added to the COMPILE_DEFINITIONS target property for each target in the
current CMakeLists file.
Definitions are specified using the syntax VAR or VAR=value. Function-style definitions are not
supported. CMake will automatically escape the value correctly for the native build system (note that
CMake language syntax may require escapes to specify some values).
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 accumulating options from the current target
and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.
New in version 3.12: While beneficial for individual options, the de-duplication step can break up option
groups. For example, -option A -option B becomes -option A B. One may specify a group of options using
shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option
string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A"
"SHELL:-option B" becomes -option A -option B.
Example
Since different compilers support different options, a typical use of this command is in a
compiler-specific conditional clause:
if (MSVC)
# warning level 4 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 preprocessor definitions and include
directories it is recommended to use the more specific commands add_compile_definitions() and
include_directories().
The command target_compile_options() adds target-specific options.
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 output:
add_custom_command(OUTPUT output1 [output2 ...]
COMMAND command1 [ARGS] [args1...]
[COMMAND command2 [ARGS] [args2...] ...]
[MAIN_DEPENDENCY depend]
[DEPENDS [depends...]]
[BYPRODUCTS [files...]]
[IMPLICIT_DEPENDS <lang1> depend1
[<lang2> depend2] ...]
[WORKING_DIRECTORY dir]
[COMMENT comment]
[DEPFILE depfile]
[JOB_POOL job_pool]
[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
generate the file using the command at build time. Do not list the output in more than one independent
target that may build in parallel or the 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 target in the following form:
OUTPUT: MAIN_DEPENDENCY DEPENDS
COMMAND
The options are:
APPEND Append the COMMAND and DEPENDS option values to the custom command for the first output specified.
There must have already been a previous call to this command with the same output.
If the previous call specified the output via a generator expression, the output specified by the
current call must match in at least one configuration after evaluating generator expressions. In
this case, the appended commands and dependencies apply to all configurations.
The COMMENT, MAIN_DEPENDENCY, and WORKING_DIRECTORY options are currently ignored when APPEND is
given, but may be used in the future.
BYPRODUCTS
New in version 3.2.
Specify the files the command is expected to produce but whose modification time may or may not be
newer than the dependencies. If a byproduct name is a relative path it will be interpreted
relative to the build tree directory corresponding to the current source directory. Each
byproduct file will be marked with the GENERATED source file property automatically.
Explicit specification of byproducts is supported by the Ninja generator to tell the ninja build
tool how to regenerate byproducts when they are missing. It is also useful when other build rules
(e.g. custom commands) depend on the byproducts. Ninja requires a build rule for any generated
file on which another rule depends even if there are order-only dependencies to ensure the
byproducts will be available before their dependents build.
The Makefile Generators will remove BYPRODUCTS and other GENERATED files during make clean.
New in version 3.20: Arguments to BYPRODUCTS may use a restricted set of generator expressions.
Target-dependent expressions are not permitted.
COMMAND
Specify the command-line(s) to execute at build time. If more than one COMMAND is specified they
will be executed in order, but not necessarily composed into a stateful shell or batch script.
(To run a full script, use the configure_file() command or the file(GENERATE) command to create
it, and then specify a COMMAND to launch it.) The optional ARGS argument is for backward
compatibility and will be ignored.
If COMMAND specifies an executable target name (created by the add_executable() command), it will
automatically be replaced by the location of the executable created at build time if either of the
following is true:
• The target is not being cross-compiled (i.e. the CMAKE_CROSSCOMPILING variable is not set to
true).
• New in version 3.6: The target is being cross-compiled and an emulator is provided (i.e. its
CROSSCOMPILING_EMULATOR target property is set). In this case, the contents of
CROSSCOMPILING_EMULATOR will be prepended to the command before the location of the target
executable.
If neither of the above conditions are met, it is assumed that the command name is a program to be
found on the PATH at build time.
Arguments to COMMAND may use generator expressions. Use the TARGET_FILE generator expression to
refer to the location of a target later in the command line (i.e. as a command argument rather
than as the command to execute).
Whenever one of the following target based generator expressions are used as a command to execute
or is mentioned in a command argument, a target-level dependency will be added automatically so
that the mentioned target will be built before any target using this custom command (see policy
CMP0112).
• TARGET_FILE
• TARGET_LINKER_FILE
• TARGET_SONAME_FILE
• TARGET_PDB_FILE
This target-level dependency does NOT add a file-level dependency that would cause the custom
command to re-run whenever the executable is recompiled. List target names with the DEPENDS
option to add such file-level dependencies.
COMMENT
Display the given message before the commands are executed at build time.
DEPENDS
Specify files on which the command depends. Each argument is converted to a dependency as
follows:
1. If the argument is the name of a target (created by the add_custom_target(), add_executable(),
or add_library() command) a target-level dependency is created to make sure the target is built
before any target using this custom command. Additionally, if the target is an executable or
library, a file-level dependency is created to cause the custom command to re-run whenever the
target is recompiled.
2. If the argument is an absolute path, a file-level dependency is created on that path.
3. If the argument is the name of a source file that has been added to a target or on which a
source file property has been set, a file-level dependency is created on that source file.
4. If the argument is a relative path and it exists in the current source directory, a file-level
dependency is created on that file in the current source directory.
5. Otherwise, a file-level dependency is created on that path relative to the current binary
directory.
If any dependency is an OUTPUT of another custom command in the same directory (CMakeLists.txt
file), CMake automatically brings the other custom command into the target in which this command
is built.
New in version 3.16: A target-level dependency is added if any dependency is listed as BYPRODUCTS
of a target or any of its build events in the same directory to ensure the byproducts will be
available.
If DEPENDS is not specified, the command will run whenever the OUTPUT is missing; if the command
does not actually create the OUTPUT, the rule will always run.
New in version 3.1: Arguments to DEPENDS may use generator expressions.
COMMAND_EXPAND_LISTS
New in version 3.8.
Lists in COMMAND arguments will be expanded, including those created with generator expressions,
allowing COMMAND arguments such as ${CC}
"-I$<JOIN:$<TARGET_PROPERTY:foo,INCLUDE_DIRECTORIES>,;-I>" foo.cc to be properly expanded.
IMPLICIT_DEPENDS
Request scanning of implicit dependencies of an input file. The language given specifies the
programming language whose corresponding dependency scanner should be used. Currently only C and
CXX language scanners are supported. The language has to be specified for every file in the
IMPLICIT_DEPENDS list. Dependencies discovered from the scanning are added to those of the custom
command at build time. Note that the IMPLICIT_DEPENDS option is currently supported only for
Makefile generators and will be ignored by other generators.
NOTE:
This option cannot be specified at the same time as DEPFILE option.
JOB_POOL
New in version 3.15.
Specify a pool for the Ninja generator. Incompatible with USES_TERMINAL, which implies the console
pool. Using a pool that is not defined by JOB_POOLS causes an error by ninja at build time.
MAIN_DEPENDENCY
Specify the primary input source file to the command. This is treated just like any value given
to the DEPENDS option but also suggests to Visual Studio generators where to hang the custom
command. Each source file may have at most one command specifying it as its main dependency. A
compile command (i.e. for a library or an executable) counts as an implicit main dependency which
gets silently overwritten by a custom command specification.
OUTPUT Specify the output files the command is expected to produce. If an output name is a relative path
it will be interpreted relative 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 possible. With the Ninja generator,
this places the command in the console pool.
VERBATIM
All arguments to the commands will be escaped properly for the build tool so that the invoked
command receives each argument unchanged. Note that one level of escapes is still used by the
CMake language processor before add_custom_command even sees the arguments. Use of VERBATIM is
recommended as it enables correct behavior. When VERBATIM is not given the behavior is platform
specific because there is no protection of tool-specific special characters.
WORKING_DIRECTORY
Execute the command with the given current working directory. If it is a relative path it will be
interpreted relative to the build tree directory corresponding to the current source directory.
New in version 3.13: Arguments to WORKING_DIRECTORY may use generator expressions.
DEPFILE
New in version 3.7.
Specify a .d depfile which holds dependencies for the custom command. It is usually emitted by
the custom command itself. This keyword may only be used if the generator supports it, as
detailed below.
New in version 3.7: The Ninja generator supports DEPFILE since the keyword was first added.
New in version 3.17: Added the Ninja Multi-Config generator, which included support for the
DEPFILE keyword.
New in version 3.20: Added support for Makefile Generators.
NOTE:
DEPFILE cannot be specified at the same time as the IMPLICIT_DEPENDS option for Makefile
Generators.
New in version 3.21: Added support for Visual Studio Generators with VS 2012 and above, and for
the Xcode generator. Support for generator expressions was also added.
Using DEPFILE with generators other than those listed above is an error.
If the DEPFILE argument is relative, it should be relative to CMAKE_CURRENT_BINARY_DIR, and any
relative paths inside the DEPFILE should also be relative to CMAKE_CURRENT_BINARY_DIR. See policy
CMP0116, which is always NEW for Makefile Generators, Visual Studio Generators, and the Xcode
generator.
Examples: Generating Files
Custom commands may be used to generate source files. For example, the code:
add_custom_command(
OUTPUT out.c
COMMAND someTool -i ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
-o out.c
DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
VERBATIM)
add_library(myLib out.c)
adds a custom command to run someTool to generate out.c and then compile the generated source as part of
a library. The generation rule will re-run whenever in.txt changes.
New in version 3.20: One may use generator expressions to specify per-configuration outputs. For
example, the code:
add_custom_command(
OUTPUT "out-$<CONFIG>.c"
COMMAND someTool -i ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
-o "out-$<CONFIG>.c"
-c "$<CONFIG>"
DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/in.txt
VERBATIM)
add_library(myLib "out-$<CONFIG>.c")
adds a custom command to run someTool to generate out-<config>.c, where <config> is the build
configuration, and then compile the generated source as part of a library.
Build Events
The second signature adds a custom command to a target such as a library or executable. This is useful
for performing an operation before or after building the target. The command becomes part of the target
and will only execute when the target itself is built. If the target is already built, the command will
not execute.
add_custom_command(TARGET <target>
PRE_BUILD | PRE_LINK | POST_BUILD
COMMAND command1 [ARGS] [args1...]
[COMMAND command2 [ARGS] [args2...] ...]
[BYPRODUCTS [files...]]
[WORKING_DIRECTORY dir]
[COMMENT comment]
[VERBATIM] [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 directory; targets defined in other directories may not be specified.
When the command will happen is determined by which of the following is specified:
PRE_BUILD
On Visual Studio Generators, run before any other rules are executed within the target. On other
generators, run just before PRE_LINK commands.
PRE_LINK
Run after sources have been compiled but before linking the binary or running the librarian or
archiver tool of a static library. This is not defined for targets created by the
add_custom_target() command.
POST_BUILD
Run after all other rules within the target have been executed.
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 2010 (and newer) generators these command lines or custom commands will be omitted for the
specific configuration and no "empty-string-command" will be added.
This allows to add individual build events for every configuration.
New in version 3.21: Support for target-dependent generator expressions.
Examples: Build Events
A POST_BUILD event may be used to post-process a binary after linking. For example, the code:
add_executable(myExe myExe.c)
add_custom_command(
TARGET myExe POST_BUILD
COMMAND someHasher -i "$<TARGET_FILE:myExe>"
-o "$<TARGET_FILE:myExe>.hash"
VERBATIM)
will run someHasher to produce a .hash file next to the executable after linking.
New in version 3.20: One may use generator expressions to specify per-configuration byproducts. For
example, the code:
add_library(myPlugin MODULE myPlugin.c)
add_custom_command(
TARGET myPlugin POST_BUILD
COMMAND someHasher -i "$<TARGET_FILE:myPlugin>"
--as-code "myPlugin-hash-$<CONFIG>.c"
BYPRODUCTS "myPlugin-hash-$<CONFIG>.c"
VERBATIM)
add_executable(myExe myExe.c "myPlugin-hash-$<CONFIG>.c")
will run someHasher after linking myPlugin, e.g. to produce a .c file containing code to check the hash
of myPlugin that the myExe executable can use to verify it before loading.
Ninja Multi-Config
New in version 3.20: add_custom_command supports the Ninja Multi-Config generator's cross-config
capabilities. See the generator documentation for more information.
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 targets.
The options are:
ALL Indicate that this target should be added to the default build target so that it will be run every
time (the command cannot be called ALL).
BYPRODUCTS
New in version 3.2.
Specify the files the command is expected to produce but whose modification time may or may not be
updated on subsequent builds. If a byproduct name is a relative path it will be interpreted
relative to the build tree directory corresponding to the current source directory. Each
byproduct file will be marked with the GENERATED source file property automatically.
Explicit specification of byproducts is supported by the Ninja generator to tell the ninja build
tool how to regenerate byproducts when they are missing. It is also useful when other build rules
(e.g. custom commands) depend on the byproducts. Ninja requires a build rule for any generated
file on which another rule depends even if there are order-only dependencies to ensure the
byproducts will be available before their dependents build.
The Makefile Generators will remove BYPRODUCTS and other GENERATED files during make clean.
New in version 3.20: Arguments to BYPRODUCTS may use a restricted set of generator expressions.
Target-dependent expressions are not permitted.
COMMAND
Specify the command-line(s) to execute at build time. If more than one COMMAND is specified they
will be executed in order, but not necessarily composed into a stateful shell or batch script.
(To run a full script, use the configure_file() command or the file(GENERATE) command to create
it, and then specify a COMMAND to launch it.)
If COMMAND specifies an executable target name (created by the add_executable() command), it will
automatically be replaced by the location of the executable created at build time if either of the
following is true:
• The target is not being cross-compiled (i.e. the CMAKE_CROSSCOMPILING variable is not set to
true).
• New in version 3.6: The target is being cross-compiled and an emulator is provided (i.e. its
CROSSCOMPILING_EMULATOR target property is set). In this case, the contents of
CROSSCOMPILING_EMULATOR will be prepended to the command before the location of the target
executable.
If neither of the above conditions are met, it is assumed that the command name is a program to be
found on the PATH at build time.
Arguments to COMMAND may use generator expressions. Use the TARGET_FILE generator expression to
refer to the location of a target later in the command line (i.e. as a command argument rather
than as the command to execute).
Whenever one of the following target based generator expressions are used as a command to execute
or is mentioned in a command argument, a target-level dependency will be added automatically so
that the mentioned target will be built before this custom target (see policy CMP0112).
• TARGET_FILE
• TARGET_LINKER_FILE
• TARGET_SONAME_FILE
• TARGET_PDB_FILE
The command and arguments are optional and if not specified an empty target will be created.
COMMENT
Display the given message before the commands are executed at build time.
DEPENDS
Reference files and outputs of custom commands created with add_custom_command() command calls in
the same directory (CMakeLists.txt file). They will be brought up to date when the target is
built.
Changed in version 3.16: A target-level dependency is added if any dependency is a byproduct of a
target or any of its build events in the same directory to ensure the byproducts will be available
before this target is built.
Use the add_dependencies() command to add dependencies on other targets.
COMMAND_EXPAND_LISTS
New in version 3.8.
Lists in COMMAND arguments will be expanded, including those created with generator expressions,
allowing COMMAND arguments such as ${CC}
"-I$<JOIN:$<TARGET_PROPERTY:foo,INCLUDE_DIRECTORIES>,;-I>" foo.cc to be properly expanded.
JOB_POOL
New in version 3.15.
Specify a pool for the Ninja generator. Incompatible with USES_TERMINAL, which implies the console
pool. Using a pool that is not defined by JOB_POOLS causes an error by ninja at build time.
SOURCES
Specify additional source files to be included in the custom target. Specified source files will
be added to IDE project files for convenience in editing even if they have no build rules.
VERBATIM
All arguments to the commands will be escaped properly for the build tool so that the invoked
command receives each argument unchanged. Note that one level of escapes is still used by the
CMake language processor before add_custom_target even sees the arguments. Use of VERBATIM is
recommended as it enables correct behavior. When VERBATIM is not given the behavior is platform
specific because there is no protection of tool-specific special characters.
USES_TERMINAL
New in version 3.2.
The command will be given direct access to the terminal if possible. With the Ninja generator,
this places the command in the console pool.
WORKING_DIRECTORY
Execute the command with the given current working directory. If it is a relative path it will be
interpreted relative to the build tree directory corresponding to the current source directory.
New in version 3.13: Arguments to WORKING_DIRECTORY may use generator expressions.
Ninja Multi-Config
New in version 3.20: add_custom_target supports the Ninja Multi-Config generator's cross-config
capabilities. See the generator documentation for more information.
add_definitions
Add -D define flags to the compilation of source files.
add_definitions(-DFOO -DBAR ...)
Adds definitions to the compiler command line for targets in the current directory, whether added before
or after this command is invoked, and for the ones in sub-directories added after. This command can be
used to add any flags, but it is intended to add preprocessor definitions.
NOTE:
This command has been superseded by alternatives:
• Use add_compile_definitions() to add preprocessor definitions.
• Use include_directories() to add include directories.
• Use add_compile_options() to add other options.
Flags beginning in -D or /D that look like preprocessor definitions are automatically added to the
COMPILE_DEFINITIONS directory property for the current directory. Definitions with non-trivial values
may be left in the set of flags instead of being converted for reasons of backwards compatibility. See
documentation of the directory, target, source file COMPILE_DEFINITIONS properties for details on adding
preprocessor definitions to specific scopes and configurations.
See the cmake-buildsystem(7) manual for more on defining buildsystem properties.
add_dependencies
Add a dependency between top-level targets.
add_dependencies(<target> [<target-dependency>]...)
Makes a top-level <target> depend on other top-level targets to ensure that they build before <target>
does. A top-level target is one created by one of the add_executable(), add_library(), or
add_custom_target() commands (but not targets generated by CMake like install).
Dependencies added to an imported target or an interface library are followed transitively in its place
since the target itself does not build.
New in version 3.3: Allow adding dependencies to interface libraries.
See 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 conventions of the native
platform (such as <name>.exe or just <name>).
New in version 3.1: Source arguments to add_executable may use "generator expressions" with the syntax
$<...>. See the cmake-generator-expressions(7) manual for available expressions.
New in version 3.11: The source files can be omitted if they are added later using target_sources().
By default the executable file will be created in the build tree directory corresponding to the source
tree directory in which the command was invoked. See documentation of the RUNTIME_OUTPUT_DIRECTORY
target property to change this location. See documentation of the OUTPUT_NAME target property to change
the <name> part of the final file name.
If WIN32 is given the property WIN32_EXECUTABLE will be set on the target created. See documentation of
that target property for details.
If MACOSX_BUNDLE is given the corresponding property will be set on the created target. See
documentation of the MACOSX_BUNDLE target property for details.
If EXCLUDE_FROM_ALL is given the corresponding property will be set on the created target. See
documentation of the EXCLUDE_FROM_ALL target property for details.
See the cmake-buildsystem(7) manual for more on defining buildsystem properties.
See also HEADER_FILE_ONLY on what to do if some sources are pre-processed, and you want to have the
original sources reachable from within IDE.
Imported Executables
add_executable(<name> IMPORTED [GLOBAL])
An IMPORTED executable target references an executable file located outside the project. No rules are
generated to build it, and the IMPORTED target property is True. The target name has scope in the
directory in which it is created and below, but the GLOBAL option extends visibility. It may be
referenced like any target built within the project. IMPORTED executables are useful for convenient
reference from commands like add_custom_command(). Details about the imported executable are specified
by setting properties whose names begin in IMPORTED_. The most important such property is
IMPORTED_LOCATION (and its per-configuration version IMPORTED_LOCATION_<CONFIG>) which specifies the
location of the main executable file on disk. See documentation of the IMPORTED_* properties for more
information.
Alias Executables
add_executable(<name> ALIAS <target>)
Creates an Alias Target, such that <name> can be used to refer to <target> in subsequent commands. The
<name> does not appear in the generated buildsystem as a make target. The <target> may not be an ALIAS.
New in version 3.11: An ALIAS can target a GLOBAL Imported Target
New in version 3.18: An ALIAS can target a non-GLOBAL Imported Target. Such alias is scoped to the
directory in which it is created and subdirectories. The ALIAS_GLOBAL target property can be used to
check if the alias is global or not.
ALIAS targets can be used as targets to read properties from, executables for custom commands and custom
targets. They can also be tested for existence with the regular if(TARGET) subcommand. The <name> may
not be used to modify properties of <target>, that is, it may not be used as the operand of
set_property(), set_target_properties(), target_link_libraries() etc. An ALIAS target may not be
installed or exported.
add_library
Add a library to the project using the specified source files.
Normal Libraries
add_library(<name> [STATIC | SHARED | MODULE]
[EXCLUDE_FROM_ALL]
[<source>...])
Adds a library target called <name> to be built from the source files listed in the command invocation.
The <name> corresponds to the logical target name and must be globally unique within a project. The
actual file name of the library built is constructed based on conventions of the native platform (such as
lib<name>.a or <name>.lib).
New in version 3.1: Source arguments to add_library may use "generator expressions" with the syntax
$<...>. See the cmake-generator-expressions(7) manual for available expressions.
New in version 3.11: The source files can be omitted if they are added later using target_sources().
STATIC, SHARED, or MODULE may be given to specify the type of library to be created. STATIC libraries
are archives of object files for use when linking other targets. SHARED libraries are linked dynamically
and loaded at runtime. MODULE libraries are plugins that are not linked into other targets but may be
loaded dynamically at runtime using dlopen-like functionality. If no type is given explicitly the type
is STATIC or SHARED based on whether the current value of the variable BUILD_SHARED_LIBS is ON. For
SHARED and MODULE libraries the POSITION_INDEPENDENT_CODE target property is set to ON automatically. A
SHARED library may be marked with the FRAMEWORK target property to create an macOS Framework.
New in version 3.8: A STATIC library may be marked with the FRAMEWORK target property to create a static
Framework.
If a library does not export any symbols, it must not be declared as a SHARED library. For example, a
Windows resource DLL or a managed C++/CLI DLL that exports no unmanaged symbols would need to be a MODULE
library. This is because CMake expects a SHARED library to always have an associated import library on
Windows.
By default the library file will be created in the build tree directory corresponding to the source tree
directory in which the command was invoked. See documentation of the ARCHIVE_OUTPUT_DIRECTORY,
LIBRARY_OUTPUT_DIRECTORY, and RUNTIME_OUTPUT_DIRECTORY target properties to change this location. See
documentation of the OUTPUT_NAME target property to change the <name> part of the final file name.
If EXCLUDE_FROM_ALL is given the corresponding property will be set on the created target. See
documentation of the EXCLUDE_FROM_ALL target property for details.
See the cmake-buildsystem(7) manual for more on defining buildsystem properties.
See also HEADER_FILE_ONLY on what to do if some sources are pre-processed, and you want to have the
original sources reachable from within IDE.
Object Libraries
add_library(<name> OBJECT [<source>...])
Creates an Object Library. An object library compiles source files but does not archive or link their
object files into a library. Instead other targets created by add_library() or add_executable() may
reference the objects using an expression of the form $<TARGET_OBJECTS:objlib> as a source, where objlib
is the object library name. For example:
add_library(... $<TARGET_OBJECTS:objlib> ...)
add_executable(... $<TARGET_OBJECTS:objlib> ...)
will include objlib's object files in a library and an executable along with those compiled from their
own sources. Object libraries may contain only sources that compile, header files, and other files that
would not affect linking of a normal library (e.g. .txt). They may contain custom commands generating
such sources, but not PRE_BUILD, PRE_LINK, or POST_BUILD commands. Some native build systems (such as
Xcode) may not like targets that have only object files, so consider adding at least one real source file
to any target that references $<TARGET_OBJECTS:objlib>.
New in version 3.12: Object libraries can be linked to with target_link_libraries().
Interface Libraries
add_library(<name> INTERFACE)
Creates an Interface Library. An INTERFACE library target does not compile sources and does not produce
a library artifact on disk. However, it may have properties set on it and it may be installed and
exported. Typically, INTERFACE_* properties are populated on an interface target using the commands:
• set_property(),
• target_link_libraries(INTERFACE),
• target_link_options(INTERFACE),
• target_include_directories(INTERFACE),
• target_compile_options(INTERFACE),
• target_compile_definitions(INTERFACE), and
• target_sources(INTERFACE),
and then it is used as an argument to target_link_libraries() like any other target.
An interface library created with the above signature has no source files itself and is not included as a
target in the generated buildsystem.
New in version 3.15: An interface library can have PUBLIC_HEADER and PRIVATE_HEADER properties. The
headers specified by those properties can be installed using the install(TARGETS) command.
New in version 3.19: An interface library target may be created with source files:
add_library(<name> INTERFACE [<source>...] [EXCLUDE_FROM_ALL])
Source files may be listed directly in the add_library call or added later by calls to target_sources()
with the PRIVATE or PUBLIC keywords.
If an interface library has source files (i.e. the SOURCES target property is set), it will appear in the
generated buildsystem as a build target much like a target defined by the add_custom_target() command.
It does not compile any sources, but does contain build rules for custom commands created by the
add_custom_command() command.
NOTE:
In most command signatures where the INTERFACE keyword appears, the items listed after it only become
part of that target's usage requirements and are not part of the target's own settings. However, in
this signature of add_library, the INTERFACE keyword refers to the library type only. Sources listed
after it in the add_library call are PRIVATE to the interface library and do not appear in its
INTERFACE_SOURCES target property.
Imported Libraries
add_library(<name> <type> IMPORTED [GLOBAL])
Creates an IMPORTED library target called <name>. No rules are generated to build it, and the IMPORTED
target property is True. The target name has scope in the directory in which it is created and below,
but the GLOBAL option extends visibility. It may be referenced like any target built within the project.
IMPORTED libraries are useful for convenient reference from commands like target_link_libraries().
Details about the imported library are specified by setting properties whose names begin in IMPORTED_ and
INTERFACE_.
The <type> must be one of:
STATIC, SHARED, MODULE, UNKNOWN
References a library file located outside the project. The IMPORTED_LOCATION target property (or
its per-configuration variant IMPORTED_LOCATION_<CONFIG>) specifies the location of the main
library file on disk:
• For a SHARED library on most non-Windows platforms, the main library file is the .so or .dylib
file used by both linkers and dynamic loaders. If the referenced library file has a SONAME (or
on macOS, has a LC_ID_DYLIB starting in @rpath/), the value of that field should be set in the
IMPORTED_SONAME target property. If the referenced library file does not have a SONAME, but the
platform supports it, then the IMPORTED_NO_SONAME target property should be set.
• For a SHARED library on Windows, the IMPORTED_IMPLIB target property (or its per-configuration
variant IMPORTED_IMPLIB_<CONFIG>) specifies the location of the DLL import library file (.lib or
.dll.a) on disk, and the IMPORTED_LOCATION is the location of the .dll runtime library (and is
optional, but needed by the TARGET_RUNTIME_DLLS generator expression).
Additional usage requirements may be specified in INTERFACE_* properties.
An UNKNOWN library type is typically only used in the implementation of Find Modules. It allows
the path to an imported library (often found using the find_library() command) to be used without
having to know what type of library it is. This is especially useful on Windows where a static
library and a DLL's import library both have the same file extension.
OBJECT References a set of object files located outside the project. The IMPORTED_OBJECTS target
property (or its per-configuration variant IMPORTED_OBJECTS_<CONFIG>) specifies the locations of
object files on disk. Additional usage requirements may be specified in INTERFACE_* properties.
INTERFACE
Does not reference any library or object files on disk, but may specify usage requirements in
INTERFACE_* properties.
See documentation of the IMPORTED_* and INTERFACE_* properties for more information.
Alias Libraries
add_library(<name> ALIAS <target>)
Creates an Alias Target, such that <name> can be used to refer to <target> in subsequent commands. The
<name> does not appear in the generated buildsystem as a make target. The <target> may not be an ALIAS.
New in version 3.11: An ALIAS can target a GLOBAL Imported Target
New in version 3.18: An ALIAS can target a non-GLOBAL Imported Target. Such alias is scoped to the
directory in which it is created and below. The ALIAS_GLOBAL target property can be used to check if the
alias is global or not.
ALIAS targets can be used as linkable targets and as targets to read properties from. They can also be
tested for existence with the regular if(TARGET) subcommand. The <name> may not be used to modify
properties of <target>, that is, it may not be used as the operand of set_property(),
set_target_properties(), target_link_libraries() etc. An ALIAS target may not be installed or exported.
add_link_options
New in version 3.13.
Add options to the link step for executable, shared library or module library targets in the current
directory and below that are added after this command is invoked.
add_link_options(<option> ...)
This command can be used to add any link options, but alternative commands exist to add libraries
(target_link_libraries() or link_libraries()). See documentation of the directory and target
LINK_OPTIONS properties.
NOTE:
This command cannot be used to add options for static library targets, since they do not use a linker.
To add archiver or MSVC librarian flags, see the STATIC_LIBRARY_OPTIONS target property.
Arguments to add_link_options may use "generator expressions" with the syntax $<...>. See the
cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for
more on defining buildsystem properties.
Host And Device Specific Link Options
New in version 3.18: When a device link step is involved, which is controlled by
CUDA_SEPARABLE_COMPILATION and CUDA_RESOLVE_DEVICE_SYMBOLS properties and policy CMP0105, the raw options
will be delivered to the host and device link steps (wrapped in -Xcompiler or equivalent for device
link). Options wrapped with $<DEVICE_LINK:...> generator expression will be used only for the device link
step. Options wrapped with $<HOST_LINK:...> generator expression will be used only for the host link
step.
Option De-duplication
The final set of options used for a target is constructed by accumulating options from the current target
and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.
New in version 3.12: While beneficial for individual options, the de-duplication step can break up option
groups. For example, -option A -option B becomes -option A B. One may specify a group of options using
shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option
string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A"
"SHELL:-option B" becomes -option A -option B.
Handling Compiler Driver Differences
To pass options to the linker tool, each compiler driver has its own syntax. The LINKER: prefix and ,
separator can be used to specify, in a portable way, options to pass to the linker tool. LINKER: is
replaced by the appropriate driver option and , by the appropriate driver separator. The driver prefix
and driver separator are given by the values of the CMAKE_<LANG>_LINKER_WRAPPER_FLAG and
CMAKE_<LANG>_LINKER_WRAPPER_FLAG_SEP variables.
For example, "LINKER:-z,defs" becomes -Xlinker -z -Xlinker defs for Clang and -Wl,-z,defs for GNU GCC.
The LINKER: prefix can be specified as part of a SHELL: prefix expression.
The LINKER: prefix supports, as an alternative syntax, specification of arguments using the SHELL: prefix
and space as separator. The previous example then becomes "LINKER:SHELL:-z defs".
NOTE:
Specifying the SHELL: prefix anywhere other than at the beginning of the LINKER: prefix is not
supported.
add_subdirectory
Add a subdirectory to the build.
add_subdirectory(source_dir [binary_dir] [EXCLUDE_FROM_ALL])
Adds a subdirectory to the build. The source_dir specifies the directory in which the source
CMakeLists.txt and code files are located. If it is a relative path it will be evaluated with respect to
the current directory (the typical usage), but it may also be an absolute path. The binary_dir specifies
the directory in which to place the output files. If it is a relative path it will be evaluated with
respect to the current output directory, but it may also be an absolute path. If binary_dir is not
specified, the value of source_dir, before expanding any relative path, will be used (the typical usage).
The CMakeLists.txt file in the specified source directory will be processed immediately by CMake before
processing in the current input file continues beyond this command.
If the EXCLUDE_FROM_ALL argument is provided then targets in the subdirectory will not be included in the
ALL target of the parent directory by default, and will be excluded from IDE project files. Users must
explicitly build targets in the subdirectory. This is meant for use when the subdirectory contains a
separate part of the project that is useful but not necessary, such as a set of examples. Typically the
subdirectory should contain its own project() command invocation so that a full build system will be
generated in the subdirectory (such as a 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.
add_test
Add a test to the project to be run by ctest(1).
add_test(NAME <name> COMMAND <command> [<arg>...]
[CONFIGURATIONS <config>...]
[WORKING_DIRECTORY <dir>]
[COMMAND_EXPAND_LISTS])
Adds a test called <name>. The test name may contain arbitrary characters, expressed as a Quoted
Argument or Bracket Argument if necessary. See policy CMP0110. The options are:
COMMAND
Specify the test command-line. If <command> specifies an executable target (created by
add_executable()) it will automatically be replaced by the location of the executable created at
build time.
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.
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.
The COMMAND and WORKING_DIRECTORY options may use "generator expressions" with the syntax $<...>. See
the cmake-generator-expressions(7) manual for available expressions.
Example usage:
add_test(NAME mytest
COMMAND testDriver --config $<CONFIG>
--exe $<TARGET_FILE:myexe>)
This creates a test mytest whose command runs a testDriver tool passing the configuration name and the
full path to the executable file produced by target myexe.
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.
----
add_test(<name> <command> [<arg>...])
Add a test called <name> with the given command-line. Unlike the above NAME signature no transformation
is performed on the command-line to support target names or generator expressions.
aux_source_directory
Find all source files in a directory.
aux_source_directory(<dir> <variable>)
Collects the names of all the source files in the specified directory and stores the list in the
<variable> provided. This command is intended to be used by projects that use explicit template
instantiation. Template instantiation files can be stored in a Templates subdirectory and collected
automatically using this command to avoid manually listing all instantiations.
It is tempting to use this command to avoid writing the list of source files for a library or executable
target. While this seems to work, there is no way for CMake to generate a build system that knows when a
new source file has been added. Normally the generated build system knows when it needs to rerun CMake
because the CMakeLists.txt file is modified to add a new source. When the source is just added to the
directory without modifying this file, one would have to manually rerun CMake to generate a build system
incorporating the new file.
build_command
Get a command line to build the current project. This is mainly intended for internal use by the CTest
module.
build_command(<variable>
[CONFIGURATION <config>]
[PARALLEL_LEVEL <parallel>]
[TARGET <target>]
[PROJECT_NAME <projname>] # legacy, causes warning
)
Sets the given <variable> to a command-line string of the form:
<cmake> --build . [--config <config>] [--parallel <parallel>] [--target <target>...] [-- -i]
where <cmake> is the location of the cmake(1) command-line tool, and <config>, <parallel> and <target>
are the values provided to the CONFIGURATION, PARALLEL_LEVEL and TARGET options, if any. The trailing --
-i option is added for Makefile Generators if policy CMP0061 is not set to NEW.
When invoked, this cmake --build command line will launch the underlying build system tool.
New in version 3.21: The PARALLEL_LEVEL argument can be used to set the --parallel flag.
build_command(<cachevariable> <makecommand>)
This second signature is deprecated, but still available for backwards compatibility. Use the first
signature instead.
It sets the given <cachevariable> to a command-line string as above but without the --target option. The
<makecommand> is ignored but should be the full path to devenv, nmake, make or one of the end user build
tools for legacy invocations.
NOTE:
In CMake versions prior to 3.0 this command returned a command line that directly invokes the native
build tool for the current generator. Their implementation of the PROJECT_NAME option had no useful
effects, so CMake now warns on use of the option.
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 arguments consist of a list of test source files, can be semicolon
separated. Each test source file should have a function in it that is the same name as the file with no
extension (foo.cxx should have int foo(int, char*[]);) driverName will be able to call each of the tests
by name on the command line. If EXTRA_INCLUDE is specified, then the next argument is included into the
generated file. If FUNCTION is specified, then the next argument is taken as a function name that is
passed 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
before calling the test main function. CMAKE_TESTDRIVER_AFTER_TESTMAIN can be set to have code that will
be placed directly after the call to the test main function.
define_property
Define and document custom properties.
define_property(<GLOBAL | DIRECTORY | TARGET | SOURCE |
TEST | VARIABLE | CACHED_VARIABLE>
PROPERTY <name> [INHERITED]
BRIEF_DOCS <brief-doc> [docs...]
FULL_DOCS <full-doc> [docs...])
Defines one property in a scope for use with the set_property() and get_property() commands. This is
primarily useful to associate documentation with property names that may be retrieved with the
get_property() command. The first argument determines the kind of scope in which the property should be
used. It must be one of the following:
GLOBAL = associated with the global namespace
DIRECTORY = associated with one directory
TARGET = associated with one target
SOURCE = associated with one source file
TEST = associated with a test named with add_test
VARIABLE = documents a CMake language variable
CACHED_VARIABLE = documents a CMake cache variable
Note that unlike set_property() and get_property() no actual scope needs to be given; only the kind of
scope is important.
The required PROPERTY option is immediately followed by the name of the property being defined.
If the INHERITED option is given, then the get_property() command will chain up to the next higher scope
when the requested property is not set in the scope given to the command.
• DIRECTORY scope chains to its parent directory's scope, continuing the walk up parent directories until
a directory has the property set or there are no more parents. If still not found at the top level
directory, it chains to the GLOBAL scope.
• TARGET, SOURCE and TEST properties chain to DIRECTORY scope, including further chaining up the
directories, etc. as needed.
Note that this scope chaining behavior only applies to calls to get_property(), get_directory_property(),
get_target_property(), get_source_file_property() and get_test_property(). There is no inheriting
behavior when setting properties, so using APPEND or APPEND_STRING with the set_property() command will
not consider inherited values when working out the contents to append to.
The BRIEF_DOCS and FULL_DOCS options are followed by strings to be associated with the property as its
brief and full documentation. Corresponding options to the get_property() command will retrieve the
documentation.
enable_language
Enable a language (CXX/C/OBJC/OBJCXX/Fortran/etc)
enable_language(<lang> [OPTIONAL] )
Enables support for the named language 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 compilers for other languages like C work
for assembly too.
This command must be called in file scope, not in a function call. Furthermore, it must be called in the
highest directory common to all targets using the named language directly for compiling sources or
indirectly through link dependencies. It is simplest to enable all needed languages in the top-level
directory of a project.
The OPTIONAL keyword is a placeholder for future implementation and does not currently work. Instead you
can use the CheckLanguage module to verify support before enabling.
enable_testing
Enable testing for current directory and below.
enable_testing()
Enables testing for this directory and below.
This command should be in the source directory root because ctest expects to find a test file in the
build directory root.
This command is automatically invoked when the CTest module is included, except if the BUILD_TESTING
option is turned off.
See also the add_test() command.
export
Export targets from the build tree for use by outside projects.
export(EXPORT <export-name> [NAMESPACE <namespace>] [FILE <filename>])
Creates a file <filename> that may be included by outside projects to import targets from the current
project's build tree. This is useful during cross-compiling to build utility executables that can run on
the host platform in one project and then import them into another project being compiled for the target
platform. If the NAMESPACE option is given the <namespace> string will be prepended to all target names
written to the file.
Target installations are associated with the export <export-name> using the EXPORT option of the
install(TARGETS) command.
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 installation tree.
The properties set on the generated IMPORTED targets will have the same values as the final values of the
input TARGETS.
export(TARGETS [target1 [target2 [...]]] [NAMESPACE <namespace>]
[APPEND] FILE <filename> [EXPORT_LINK_INTERFACE_LIBRARIES])
This signature is similar to the EXPORT signature, but targets are listed explicitly rather than
specified as an export-name. If the APPEND option is given the generated code will be appended to the
file instead of overwriting it. The EXPORT_LINK_INTERFACE_LIBRARIES keyword, if present, causes the
contents of the properties matching (IMPORTED_)?LINK_INTERFACE_LIBRARIES(_<CONFIG>)? to be exported, when
policy CMP0022 is NEW. If a library target is included in the export but a target to which it links is
not included the behavior is unspecified.
NOTE:
Object Libraries under Xcode have special handling if multiple architectures are listed in
CMAKE_OSX_ARCHITECTURES. In this case they will be exported as Interface Libraries with no object
files available to clients. This is sufficient to satisfy transitive usage requirements of other
targets that link to the object libraries in their implementation.
export(PACKAGE <PackageName>)
Store the current build directory in the CMake user package registry for package <PackageName>. The
find_package() command may consider the directory while searching for package <PackageName>. This helps
dependent projects find and use a package from the current project's build tree without help from the
user. Note that the entry in the package registry that this command creates works only in conjunction
with a package configuration file (<PackageName>Config.cmake) that works with the build tree. In some
cases, for example for packaging and for system wide installations, it is not desirable to write the user
package registry.
Changed in version 3.1: If the CMAKE_EXPORT_NO_PACKAGE_REGISTRY variable is enabled, the export(PACKAGE)
command will do nothing.
Changed in version 3.15: By default the export(PACKAGE) command does nothing (see policy CMP0090) because
populating the user package registry has effects outside the source and build trees. Set the
CMAKE_EXPORT_PACKAGE_REGISTRY variable to add build directories to the CMake user package registry.
export(TARGETS [target1 [target2 [...]]] [ANDROID_MK <filename>])
New in version 3.7.
This signature exports cmake built targets to the android ndk build system by creating an Android.mk file
that references the prebuilt targets. The Android NDK supports the use of prebuilt libraries, both static
and shared. This allows cmake to build the libraries of a project and make them available to an ndk
build system complete with transitive dependencies, include flags and defines required to use the
libraries. The signature takes a list of targets and puts them in the Android.mk file specified by the
<filename> given. This signature can only be used if policy CMP0022 is NEW for all targets given. A error
will be issued if that policy is set to OLD for one of the targets.
fltk_wrap_ui
Create FLTK user interfaces Wrappers.
fltk_wrap_ui(resultingLibraryName source1
source2 ... sourceN )
Produce .h and .cxx files for all the .fl and .fld files listed. The resulting .h and .cxx files will be
added to a variable named resultingLibraryName_FLTK_UI_SRCS which should be added to your library.
get_source_file_property
Get a property for a source file.
get_source_file_property(<variable> <file>
[DIRECTORY <dir> | TARGET_DIRECTORY <target>]
<property>)
Gets a property from a source file. The value of the property is stored in the specified <variable>. If
the source 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 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, either by having added it through a call to add_subdirectory() or
<dir> being the top level source directory. Relative paths are treated as relative to the current
source directory.
TARGET_DIRECTORY <target>
The source file property will be read from the directory scope in which <target> was created
(<target> must therefore already exist).
Use set_source_files_properties() to set property values. Source file properties usually control how the
file is built. One property that is always there is LOCATION.
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 relevant 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 Target Properties 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 depends 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 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.
For a list of standard properties you can type cmake --help-property-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 include files. Relative paths are
interpreted as relative to the current source directory.
The include directories are added to the INCLUDE_DIRECTORIES directory property for the current
CMakeLists file. They are also added to the INCLUDE_DIRECTORIES target property for each target in the
current CMakeLists file. The target property values are the ones used by the generators.
By default the directories specified are appended onto the current list of directories. This default
behavior can be changed by setting CMAKE_INCLUDE_DIRECTORIES_BEFORE to ON. By using AFTER or BEFORE
explicitly, you can select between appending and prepending, independent of the default.
If the SYSTEM option is given, the compiler will be told the directories are meant as system include
directories on some platforms. Signalling this setting might achieve effects such as the compiler
skipping warnings, or these fixed-install system files not being considered in dependency calculations -
see compiler docs.
Arguments to include_directories may use "generator expressions" with the syntax "$<...>". See the
cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for
more on defining buildsystem properties.
NOTE:
Prefer the target_include_directories() command to add include directories to individual targets and
optionally propagate/export them to dependents.
include_external_msproject
Include an external Microsoft project file in a workspace.
include_external_msproject(projectname location
[TYPE projectTypeGUID]
[GUID projectGUID]
[PLATFORM platformName]
dep1 dep2 ...)
Includes an external Microsoft project in the generated workspace file. Currently does nothing on UNIX.
This will create a target named [projectname]. This can be used in the add_dependencies() command to
make things depend on the external project.
TYPE, GUID and PLATFORM are optional parameters that allow one to specify the type of project, id (GUID)
of the project and the name of the target platform. This is useful for projects requiring values other
than the default (e.g. WIX projects).
New in version 3.9: If the imported project has different configuration names than the current project,
set the MAP_IMPORTED_CONFIG_<CONFIG> target property to specify the mapping.
include_regular_expression
Set the regular expression used for dependency checking.
include_regular_expression(regex_match [regex_complain])
Sets the regular expressions used in dependency checking. Only files matching regex_match will be traced
as dependencies. Only files matching regex_complain will generate warnings if they cannot be found
(standard header paths are not searched). The defaults are:
regex_match = "^.*$" (match everything)
regex_complain = "^$" (match empty string only)
install
Specify rules to run at install time.
Synopsis
install(TARGETS <target>... [...])
install(IMPORTED_RUNTIME_ARTIFACTS <target>... [...])
install({FILES | PROGRAMS} <file>... [...])
install(DIRECTORY <dir>... [...])
install(SCRIPT <file> [...])
install(CODE <code> [...])
install(EXPORT <export-name> [...])
install(RUNTIME_DEPENDENCY_SET <set-name> [...])
Introduction
This command generates installation rules for a project. Install rules specified by calls to the
install() command within a source directory are executed in order during installation.
Changed in version 3.14: Install rules in subdirectories added by calls to the add_subdirectory() command
are interleaved with those in the parent directory to run in the order declared (see policy CMP0082).
Changed in version 3.22: The environment variable CMAKE_INSTALL_MODE can override the default copying
behavior of install().
There are multiple signatures for this command. Some of them define installation options for files and
targets. Options common to multiple signatures are covered here but they are valid only for signatures
that specify them. The common options are:
DESTINATION
Specify the directory on disk to which a file will be installed. Arguments can be relative or
absolute paths.
If a relative path is given it is interpreted relative to the value of the CMAKE_INSTALL_PREFIX
variable. The prefix can be relocated at install time using the DESTDIR mechanism explained in
the CMAKE_INSTALL_PREFIX variable documentation.
If an absolute path (with a leading slash or drive letter) is given it is used verbatim.
As absolute paths are not supported by cpack installer generators, it is preferable to use
relative paths throughout. In particular, there is no need to make paths absolute by prepending
CMAKE_INSTALL_PREFIX; this prefix is used by default if the DESTINATION is a relative path.
PERMISSIONS
Specify permissions for installed files. Valid permissions are OWNER_READ, OWNER_WRITE,
OWNER_EXECUTE, GROUP_READ, GROUP_WRITE, GROUP_EXECUTE, WORLD_READ, WORLD_WRITE, WORLD_EXECUTE,
SETUID, and SETGID. Permissions that do not make sense on certain platforms are ignored on those
platforms.
CONFIGURATIONS
Specify a list of build configurations for which the install rule applies (Debug, Release, etc.).
Note that the values specified for this option only apply to options listed AFTER the
CONFIGURATIONS 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 component-specific installation only install rules associated
with the given component name will be executed. During a full installation all components are
installed unless marked with EXCLUDE_FROM_ALL. If COMPONENT is not provided a default component
"Unspecified" is created. The default component name may be controlled with the
CMAKE_INSTALL_DEFAULT_COMPONENT_NAME variable.
EXCLUDE_FROM_ALL
New in version 3.6.
Specify that the file is excluded from a full installation and only installed as part of a
component-specific installation
RENAME 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]
[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 installed:
ARCHIVE
Target artifacts of this kind include:
• Static libraries (except on macOS when marked as FRAMEWORK, see below);
• DLL import libraries (on all Windows-based systems including Cygwin; they have extension .lib,
in contrast to the .dll libraries that go to RUNTIME);
• On AIX, the linker import file created for executables with ENABLE_EXPORTS enabled.
LIBRARY
Target artifacts of this kind include:
• Shared libraries, except
• DLLs (these go to RUNTIME, see below),
• on macOS when marked as FRAMEWORK (see below).
RUNTIME
Target artifacts of this kind include:
• Executables (except on macOS when marked as MACOSX_BUNDLE, see BUNDLE below);
• DLLs (on all Windows-based systems including Cygwin; note that the accompanying import libraries
are of kind ARCHIVE).
OBJECTS
New in version 3.9.
Object files associated with object libraries.
FRAMEWORK
Both static and shared libraries marked with the FRAMEWORK property are treated as FRAMEWORK
targets on macOS.
BUNDLE Executables marked with the MACOSX_BUNDLE property are treated as BUNDLE targets on macOS.
PUBLIC_HEADER
Any PUBLIC_HEADER files associated with a library are installed in the destination specified by
the PUBLIC_HEADER argument on non-Apple platforms. Rules defined by this argument are ignored for
FRAMEWORK libraries on Apple platforms because the associated files are installed into the
appropriate locations inside the framework folder. See PUBLIC_HEADER for details.
PRIVATE_HEADER
Similar to PUBLIC_HEADER, but for PRIVATE_HEADER files. See PRIVATE_HEADER for details.
RESOURCE
Similar to PUBLIC_HEADER and PRIVATE_HEADER, but for RESOURCE files. See RESOURCE for details.
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. If
only one is given then only targets of that type will be installed (which can be used to install just a
DLL or just an import library.)
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 the public and private headers associated with the installed targets
through the PUBLIC_HEADER and PRIVATE_HEADER target properties. A destination must always be provided
for module libraries, Apple bundles and frameworks. A destination can be omitted for interface and
object libraries, but they are handled differently (see the discussion of this topic toward the end of
this section).
The following table shows the target types with their associated variables and built-in defaults that
apply when no destination is given:
┌───────────────┬─────────────────────────────┬──────────────────┐
│Target Type │ GNUInstallDirs Variable │ Built-In Default │
├───────────────┼─────────────────────────────┼──────────────────┤
│RUNTIME │ ${CMAKE_INSTALL_BINDIR} │ bin │
├───────────────┼─────────────────────────────┼──────────────────┤
│LIBRARY │ ${CMAKE_INSTALL_LIBDIR} │ lib │
├───────────────┼─────────────────────────────┼──────────────────┤
│ARCHIVE │ ${CMAKE_INSTALL_LIBDIR} │ lib │
├───────────────┼─────────────────────────────┼──────────────────┤
│PRIVATE_HEADER │ ${CMAKE_INSTALL_INCLUDEDIR} │ include │
├───────────────┼─────────────────────────────┼──────────────────┤
│PUBLIC_HEADER │ ${CMAKE_INSTALL_INCLUDEDIR} │ include │
└───────────────┴─────────────────────────────┴──────────────────┘
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.
To make packages compliant with distribution filesystem layout policies, if projects must specify a
DESTINATION, it is recommended that they use a path that begins with the appropriate GNUInstallDirs
variable. This allows package maintainers to control the install destination by setting the appropriate
cache variables. The following example shows a static library being installed to the default destination
provided by GNUInstallDirs, but with its headers installed to a project-specific subdirectory that
follows the above recommendation:
add_library(mylib STATIC ...)
set_target_properties(mylib PROPERTIES PUBLIC_HEADER mylib.h)
include(GNUInstallDirs)
install(TARGETS mylib
PUBLIC_HEADER
DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/myproj
)
In addition to the common options listed above, each target can accept the following additional
arguments:
NAMELINK_COMPONENT
New in version 3.12.
On some platforms a versioned shared library has a symbolic link such as:
lib<name>.so -> lib<name>.so.1
where lib<name>.so.1 is the soname of the library and lib<name>.so is a "namelink" allowing
linkers to find the library when given -l<name>. The NAMELINK_COMPONENT option is similar to the
COMPONENT option, but it changes the installation component of a shared library namelink if one is
generated. If not specified, this defaults to the value of COMPONENT. It is an error to use this
parameter outside of a LIBRARY block.
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 without the library. (If you don't also install the Libraries
component, 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 Debian systems, the library is expected to be in the runtime package,
and the headers and namelink are expected to be in the development package.
See the VERSION and SOVERSION target properties for details on creating versioned shared
libraries.
NAMELINK_ONLY
This option causes the installation of only the namelink when a library target is installed. On
platforms where versioned shared libraries do not have namelinks or when a library is not
versioned, the NAMELINK_ONLY option installs nothing. It is an error to use this parameter outside
of a LIBRARY block.
When NAMELINK_ONLY is given, either NAMELINK_COMPONENT or COMPONENT may be used to specify the
installation component of the namelink, but COMPONENT should generally be preferred.
NAMELINK_SKIP
Similar to NAMELINK_ONLY, but it has the opposite effect: it causes the installation of library
files other than the namelink when a library target is installed. When neither NAMELINK_ONLY or
NAMELINK_SKIP are given, both portions are installed. On platforms where versioned shared
libraries do not have symlinks or when a library is not versioned, NAMELINK_SKIP installs the
library. It is an error to use this parameter outside of a LIBRARY block.
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.
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 executable, shared library, and module
targets to be added to the specified runtime dependency set. This set can then be installed with
an install(RUNTIME_DEPENDENCY_SET) command.
This keyword and the RUNTIME_DEPENDENCIES keyword are mutually exclusive.
RUNTIME_DEPENDENCIES
New in version 3.21.
This option causes all runtime dependencies of installed executable, shared library, and module
targets to be installed along with the targets themselves. The RUNTIME, LIBRARY, FRAMEWORK, and
generic arguments are used to determine the properties (DESTINATION, COMPONENT, etc.) of the
installation of these dependencies.
RUNTIME_DEPENDENCIES is semantically equivalent to the following pair of calls:
install(TARGETS ... RUNTIME_DEPENDENCY_SET <set-name>)
install(RUNTIME_DEPENDENCY_SET <set-name> 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 <prefix>/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 sufficient to satisfy transitive
usage requirements of other targets that link to the object libraries in their implementation.
Installing a target with the EXCLUDE_FROM_ALL target property set to TRUE has undefined behavior.
New in version 3.3: An install destination given as a DESTINATION argument may use "generator
expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available
expressions.
New in version 3.13: install(TARGETS) can install targets that were created in other directories. When
using such cross-directory install rules, running make install (or similar) from a subdirectory will not
guarantee that targets from other directories are up-to-date. You can use target_link_libraries() or
add_dependencies() to ensure that such out-of-directory targets are built before the
subdirectory-specific install rules are run.
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
installation. The LIBRARY, RUNTIME, FRAMEWORK, and BUNDLE arguments have the same semantics that they do
in the TARGETS mode. Only the runtime artifacts of imported targets are installed (except in the case of
FRAMEWORK libraries, MACOSX_BUNDLE executables, and BUNDLE CFBundles.) For example, headers and import
libraries associated with DLLs are not installed. In the case of FRAMEWORK libraries, MACOSX_BUNDLE
executables, and BUNDLE CFBundles, the entire directory is installed.
The RUNTIME_DEPENDENCY_SET option causes the runtime artifacts of the imported executable, shared
library, and module library targets to be added to the <set-name> runtime dependency set. This set can
then be installed with an install(RUNTIME_DEPENDENCY_SET) command.
Installing Files
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 default permissions for the installed
file also include OWNER_EXECUTE, GROUP_EXECUTE, and WORLD_EXECUTE. This form is intended to install
programs that are not targets, such as shell scripts. Use the TARGETS form to install targets built
within the project.
The list of files... given to FILES or PROGRAMS may use "generator expressions" with the syntax $<...>.
See the cmake-generator-expressions(7) manual for available expressions. However, if any item begins in
a generator expression it must evaluate to a full path.
Either a TYPE or a DESTINATION must be provided, but not both. A TYPE argument specifies the generic
file type of the files being installed. A destination will then be set automatically by taking the
corresponding variable from GNUInstallDirs, or by using a built-in default if that variable is not
defined. See the table below for the supported file types and their corresponding variables and built-in
defaults. Projects can provide a DESTINATION argument instead of a file type if they wish to explicitly
define the install destination.
┌──────────────┬────────────────────────────────┬───────────────────────┐
│TYPE Argument │ GNUInstallDirs Variable │ Built-In Default │
├──────────────┼────────────────────────────────┼───────────────────────┤
│BIN │ ${CMAKE_INSTALL_BINDIR} │ bin │
├──────────────┼────────────────────────────────┼───────────────────────┤
│SBIN │ ${CMAKE_INSTALL_SBINDIR} │ sbin │
├──────────────┼────────────────────────────────┼───────────────────────┤
│LIB │ ${CMAKE_INSTALL_LIBDIR} │ lib │
├──────────────┼────────────────────────────────┼───────────────────────┤
│INCLUDE │ ${CMAKE_INSTALL_INCLUDEDIR} │ include │
├──────────────┼────────────────────────────────┼───────────────────────┤
│SYSCONF │ ${CMAKE_INSTALL_SYSCONFDIR} │ etc │
├──────────────┼────────────────────────────────┼───────────────────────┤
│SHAREDSTATE │ ${CMAKE_INSTALL_SHARESTATEDIR} │ com │
├──────────────┼────────────────────────────────┼───────────────────────┤
│LOCALSTATE │ ${CMAKE_INSTALL_LOCALSTATEDIR} │ var │
├──────────────┼────────────────────────────────┼───────────────────────┤
│RUNSTATE │ ${CMAKE_INSTALL_RUNSTATEDIR} │ <LOCALSTATE dir>/run │
├──────────────┼────────────────────────────────┼───────────────────────┤
│DATA │ ${CMAKE_INSTALL_DATADIR} │ <DATAROOT dir> │
├──────────────┼────────────────────────────────┼───────────────────────┤
│INFO │ ${CMAKE_INSTALL_INFODIR} │ <DATAROOT dir>/info │
├──────────────┼────────────────────────────────┼───────────────────────┤
│LOCALE │ ${CMAKE_INSTALL_LOCALEDIR} │ <DATAROOT dir>/locale │
├──────────────┼────────────────────────────────┼───────────────────────┤
│MAN │ ${CMAKE_INSTALL_MANDIR} │ <DATAROOT dir>/man │
├──────────────┼────────────────────────────────┼───────────────────────┤
│DOC │ ${CMAKE_INSTALL_DOCDIR} │ <DATAROOT dir>/doc │
└──────────────┴────────────────────────────────┴───────────────────────┘
Projects wishing to follow the common practice of installing headers into a project-specific subdirectory
will need to provide a destination rather than rely on the above.
Note that some of the types' built-in defaults use the DATAROOT directory as a prefix. The DATAROOT
prefix is calculated similarly to the types, with CMAKE_INSTALL_DATAROOTDIR as the variable and share as
the built-in default. You cannot use DATAROOT as a TYPE parameter; please use DATA instead.
To make packages compliant with distribution filesystem layout policies, if projects must specify a
DESTINATION, it is recommended that they use a path that begins with the appropriate GNUInstallDirs
variable. This allows package maintainers to control the install destination by setting the appropriate
cache variables. The following example shows how to follow this advice while installing headers to a
project-specific subdirectory:
include(GNUInstallDirs)
install(FILES mylib.h
DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/myproj
)
New in version 3.4: An install destination given as a DESTINATION argument may use "generator
expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available
expressions.
New in version 3.20: An install rename given as a RENAME argument may use "generator expressions" with
the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions.
Installing Directories
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 directory will be created but
nothing will be installed into it. The FILE_PERMISSIONS and DIRECTORY_PERMISSIONS options specify
permissions given to files and directories in the destination. If USE_SOURCE_PERMISSIONS is specified
and FILE_PERMISSIONS is not, file permissions will be copied from the source directory structure. If no
permissions are specified files will be given the default permissions specified in the FILES form of the
command, and the directories will be given the default permissions specified in the PROGRAMS form of the
command.
New in version 3.1: The MESSAGE_NEVER option disables file installation status output.
Installation of directories may be controlled with fine granularity using the PATTERN or REGEX options.
These "match" options specify a globbing pattern or regular expression to match directories or files
encountered within input directories. They may be used to apply certain options (see below) to a subset
of the files and directories encountered. The full path to each input file or directory (with forward
slashes) is matched against the expression. A PATTERN will match only complete file names: the portion
of the full path matching the pattern must occur at the end of the file name and be preceded by a slash.
A REGEX will match any portion of the full path but it may use / and $ to simulate the PATTERN behavior.
By default all files and directories are installed whether or not they are matched. The FILES_MATCHING
option may be given before the first match option to disable installation of files (but not directories)
not matched by any expression. For example, the code
install(DIRECTORY src/ DESTINATION include/myproj
FILES_MATCHING PATTERN "*.h")
will extract and install header files from a source tree.
Some options may follow a PATTERN or REGEX expression as described under string(REGEX) and are applied
only to files or directories matching them. The EXCLUDE option will skip the matched file or directory.
The PERMISSIONS option overrides the permissions setting for the matched file or directory. For example
the code
install(DIRECTORY icons scripts/ DESTINATION share/myproj
PATTERN "CVS" EXCLUDE
PATTERN "scripts/*"
PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ
GROUP_EXECUTE GROUP_READ)
will install the icons directory to share/myproj/icons and the scripts directory to share/myproj. The
icons will get default file permissions, the scripts will be given specific permissions, and any CVS
directories will be excluded.
Either a TYPE or a DESTINATION must be provided, but not both. A TYPE argument specifies the generic
file type of the files within the listed directories being installed. A destination will then be set
automatically by taking the corresponding variable from GNUInstallDirs, or by using a built-in default if
that variable is not defined. See the table below for the supported file types and their corresponding
variables and built-in defaults. Projects can provide a DESTINATION argument instead of a file type if
they wish to explicitly define the install destination.
┌──────────────┬────────────────────────────────┬───────────────────────┐
│TYPE Argument │ GNUInstallDirs Variable │ Built-In Default │
├──────────────┼────────────────────────────────┼───────────────────────┤
│BIN │ ${CMAKE_INSTALL_BINDIR} │ bin │
├──────────────┼────────────────────────────────┼───────────────────────┤
│SBIN │ ${CMAKE_INSTALL_SBINDIR} │ sbin │
├──────────────┼────────────────────────────────┼───────────────────────┤
│LIB │ ${CMAKE_INSTALL_LIBDIR} │ lib │
├──────────────┼────────────────────────────────┼───────────────────────┤
│INCLUDE │ ${CMAKE_INSTALL_INCLUDEDIR} │ include │
├──────────────┼────────────────────────────────┼───────────────────────┤
│SYSCONF │ ${CMAKE_INSTALL_SYSCONFDIR} │ etc │
├──────────────┼────────────────────────────────┼───────────────────────┤
│SHAREDSTATE │ ${CMAKE_INSTALL_SHARESTATEDIR} │ com │
├──────────────┼────────────────────────────────┼───────────────────────┤
│LOCALSTATE │ ${CMAKE_INSTALL_LOCALSTATEDIR} │ var │
├──────────────┼────────────────────────────────┼───────────────────────┤
│RUNSTATE │ ${CMAKE_INSTALL_RUNSTATEDIR} │ <LOCALSTATE dir>/run │
├──────────────┼────────────────────────────────┼───────────────────────┤
│DATA │ ${CMAKE_INSTALL_DATADIR} │ <DATAROOT dir> │
├──────────────┼────────────────────────────────┼───────────────────────┤
│INFO │ ${CMAKE_INSTALL_INFODIR} │ <DATAROOT dir>/info │
├──────────────┼────────────────────────────────┼───────────────────────┤
│LOCALE │ ${CMAKE_INSTALL_LOCALEDIR} │ <DATAROOT dir>/locale │
├──────────────┼────────────────────────────────┼───────────────────────┤
│MAN │ ${CMAKE_INSTALL_MANDIR} │ <DATAROOT dir>/man │
├──────────────┼────────────────────────────────┼───────────────────────┤
│DOC │ ${CMAKE_INSTALL_DOCDIR} │ <DATAROOT dir>/doc │
└──────────────┴────────────────────────────────┴───────────────────────┘
Note that some of the types' built-in defaults use the DATAROOT directory as a prefix. The DATAROOT
prefix is calculated similarly to the types, with CMAKE_INSTALL_DATAROOTDIR as the variable and share as
the built-in default. You cannot use DATAROOT as a TYPE parameter; please use DATA instead.
To make packages compliant with distribution filesystem layout policies, if projects must specify a
DESTINATION, it is recommended that they use a path that begins with the appropriate GNUInstallDirs
variable. This allows package maintainers to control the install destination by setting the appropriate
cache variables.
New in version 3.4: An install destination given as a DESTINATION argument may use "generator
expressions" with the syntax $<...>. See the cmake-generator-expressions(7) manual for available
expressions.
New in version 3.5: The list of dirs... given to DIRECTORY may use "generator expressions" too.
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 installation. If the script file name is
a relative path it will be interpreted with respect to the current source directory. The CODE form will
invoke the given CMake code during installation. Code is specified as a single argument inside a
double-quoted string. For example, the code
install(CODE "MESSAGE(\"Sample install message.\")")
will print a message during installation.
New in version 3.21: When the ALL_COMPONENTS option is given, the custom installation script code will be
executed for every component of a component-specific installation. This option is mutually exclusive
with the COMPONENT option.
New in version 3.14: <file> or <code> may use "generator expressions" with the syntax $<...> (in the case
of <file>, this refers to their use in the file name, not the file's contents). See the
cmake-generator-expressions(7) manual for available expressions.
Installing Exports
install(EXPORT <export-name> DESTINATION <dir>
[NAMESPACE <namespace>] [[FILE <name>.cmake]|
[PERMISSIONS permissions...]
[CONFIGURATIONS [Debug|Release|...]]
[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_LIBRARIES keyword, if present, causes the contents of the
properties matching (IMPORTED_)?LINK_INTERFACE_LIBRARIES(_<CONFIG>)? to be exported, when policy CMP0022
is NEW.
NOTE:
The installed <export-name>.cmake file may come with additional per-configuration
<export-name>-*.cmake files to be loaded by globbing. Do not use an export name that is the same as
the package name in combination with installing a <package-name>-config.cmake file or the latter may
be incorrectly matched by the glob and loaded.
When a COMPONENT option is given, the listed <component> implicitly depends on all components mentioned
in the export set. The exported <name>.cmake file will require each of the exported components to be
present in order for dependent projects to build properly. For example, a project may define components
Runtime and Development, with shared libraries going into the Runtime component and static libraries and
headers going into the Development component. The export set would also typically be part of the
Development component, but it would export targets from both the Runtime and Development components.
Therefore, the Runtime component would need to be installed if the Development component was installed,
but not vice versa. If the Development component was installed without the Runtime component, dependent
projects that try to link against it would have build errors. Package managers, such as APT and RPM,
typically handle this by listing the Runtime component as a dependency of the Development component in
the package metadata, ensuring that the library is always installed if the headers and CMake export file
are present.
New in version 3.7: In addition to cmake language files, the EXPORT_ANDROID_MK mode maybe used to specify
an export to the android ndk build system. This mode accepts the same options as the normal export mode.
The Android NDK supports the use of prebuilt libraries, both static and shared. This allows cmake to
build the libraries of a project and make them available to an ndk build system complete with transitive
dependencies, include flags and defines required to use the libraries.
The EXPORT form is useful to help outside projects use targets built and installed by the current
project. For example, the code
install(TARGETS myexe EXPORT myproj DESTINATION bin)
install(EXPORT myproj NAMESPACE mp_ DESTINATION lib/myproj)
install(EXPORT_ANDROID_MK myproj DESTINATION share/ndk-modules)
will install the executable myexe to <prefix>/bin and code to import it in the file
<prefix>/lib/myproj/myproj.cmake and <prefix>/share/ndk-modules/Android.mk. An outside project may load
this file with the include command and reference the myexe executable from the installation tree using
the imported target name mp_myexe as if the target were built in its own tree.
NOTE:
This command supersedes the install_targets() command and the PRE_INSTALL_SCRIPT and
POST_INSTALL_SCRIPT target properties. It also replaces the FILES forms of the install_files() and
install_programs() commands. The processing order of these install rules relative to those generated
by install_targets(), install_files(), and install_programs() commands is not defined.
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 installed in the RUNTIME destination and component on DLL platforms, and in the
LIBRARY destination and component on non-DLL platforms. macOS frameworks are installed in the FRAMEWORK
destination and component. Targets built within the build tree will never be installed as runtime
dependencies, nor will their own dependencies, unless the targets themselves are installed with
install(TARGETS).
The generated install script calls file(GET_RUNTIME_DEPENDENCIES) on the build-tree files to calculate
the runtime dependencies. The build-tree executable files are passed as the EXECUTABLES argument, the
build-tree shared libraries as the LIBRARIES argument, and the build-tree modules as the MODULES
argument. On macOS, if one of the executables is a MACOSX_BUNDLE, that executable is passed as the
BUNDLE_EXECUTABLE argument. At most one such bundle executable may be in the runtime dependency set on
macOS. The MACOSX_BUNDLE property has no effect on other platforms. Note that
file(GET_RUNTIME_DEPENDENCIES) only supports collecting the runtime dependencies for Windows, Linux and
macOS platforms, so install(RUNTIME_DEPENDENCY_SET) has the same limitation.
The following sub-arguments are forwarded through as the corresponding arguments to
file(GET_RUNTIME_DEPENDENCIES) (for those that provide a non-empty list of directories, regular
expressions or files). They all support generator expressions.
• DIRECTORIES <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 --install argument of cmake(1)
instead.
The install() command generates a file, cmake_install.cmake, inside the build directory, which is used
internally by the generated install target and by CPack. You can also invoke this script manually with
cmake -P. This script accepts several variables:
COMPONENT
Set this variable to install only a single CPack component as opposed to all of them. For example,
if you only want to install the Development component, run cmake -DCOMPONENT=Development -P
cmake_install.cmake.
BUILD_TYPE
Set this variable to change the build type if you are using a multi-config generator. For example,
to install with the Debug configuration, run cmake -DBUILD_TYPE=Debug -P cmake_install.cmake.
DESTDIR
This is an environment variable rather than a CMake variable. It allows you to change the
installation prefix on UNIX systems. See DESTDIR for details.
link_directories
Add directories in which the linker will look for libraries.
link_directories([AFTER|BEFORE] directory1 [directory2 ...])
Adds the paths in which the linker should search for libraries. Relative paths given to this command are
interpreted as relative to the current source directory, see CMP0015.
The command will apply only to targets created after it is called.
New in version 3.13: The directories are added to the LINK_DIRECTORIES directory property for the current
CMakeLists.txt file, converting relative paths to absolute as needed. See the cmake-buildsystem(7)
manual for more on defining buildsystem properties.
New in version 3.13: By default the directories specified are appended onto the current list of
directories. This default behavior can be changed by setting CMAKE_LINK_DIRECTORIES_BEFORE to ON. By
using AFTER or BEFORE explicitly, you can select between appending and prepending, independent of the
default.
New in version 3.13: Arguments to link_directories may use "generator expressions" with the syntax
"$<...>". See the cmake-generator-expressions(7) manual for available expressions.
NOTE:
This command is rarely necessary and should be avoided where there are other choices. Prefer to pass
full absolute paths to libraries where possible, since this ensures the correct library will always be
linked. The find_library() command provides the full path, which can generally be used directly in
calls to target_link_libraries(). Situations where a library search path may be needed include:
• Project generators like Xcode where the user can switch target architecture at build time, but a
full path to a library cannot be used because it only provides one architecture (i.e. it is not a
universal binary).
• Libraries may themselves have other private library dependencies that expect to be found via RPATH
mechanisms, but some linkers are not able to fully decode those paths (e.g. due to the presence of
things like $ORIGIN).
If a library search path must be provided, prefer to localize the effect where possible by using the
target_link_directories() command rather than link_directories(). The target-specific command can
also control how the search directories propagate to other dependent targets.
link_libraries
Link libraries to all targets added later.
link_libraries([item1 [item2 [...]]]
[[debug|optimized|general] <item>] ...)
Specify libraries or flags to use when linking any targets created later in the current directory or
below by commands such as add_executable() or add_library(). See the target_link_libraries() command for
meaning of arguments.
NOTE:
The target_link_libraries() command should be preferred whenever possible. Library dependencies are
chained automatically, so directory-wide specification of link libraries is rarely needed.
load_cache
Load in the values from another project's CMake cache.
load_cache(pathToBuildDirectory READ_WITH_PREFIX prefix entry1...)
Reads the cache and store the requested entries in variables with their name prefixed with the given
prefix. This only reads the values, and does not create entries in the local project's cache.
load_cache(pathToBuildDirectory [EXCLUDE entry1...]
[INCLUDE_INTERNALS entry1...])
Loads in the values from another cache and store them in the local project's cache as internal entries.
This is useful for a project that depends on another project built in a different tree. EXCLUDE option
can be used to provide a list of entries to be excluded. INCLUDE_INTERNALS can be used to provide a list
of internal entries to be included. Normally, no internal entries are brought in. Use of this form of
the command is strongly discouraged, but it is provided for backward compatibility.
project
Set the name of the project.
Synopsis
project(<PROJECT-NAME> [<language-name>...])
project(<PROJECT-NAME>
[VERSION <major>[.<minor>[.<patch>[.<tweak>]]]]
[DESCRIPTION <project-description-string>]
[HOMEPAGE_URL <url-string>]
[LANGUAGES <language-name>...])
Sets the name of the project, and stores it in the variable PROJECT_NAME. When called from the top-level
CMakeLists.txt also stores the project name in the variable CMAKE_PROJECT_NAME.
Also sets the variables:
PROJECT_SOURCE_DIR, <PROJECT-NAME>_SOURCE_DIR
Absolute path to the source directory for the project.
PROJECT_BINARY_DIR, <PROJECT-NAME>_BINARY_DIR
Absolute path to the binary directory for the project.
PROJECT_IS_TOP_LEVEL, <PROJECT-NAME>_IS_TOP_LEVEL
New in version 3.21.
Boolean value indicating whether the project is top-level.
Further variables are set by the optional arguments described in the following. If any of these
arguments is not used, then the corresponding variables are set to the empty string.
Options
The options are:
VERSION <version>
Optional; may not be used unless policy CMP0048 is set to NEW.
Takes a <version> argument composed of non-negative integer components, i.e.
<major>[.<minor>[.<patch>[.<tweak>]]], and sets the variables
• PROJECT_VERSION, <PROJECT-NAME>_VERSION
• PROJECT_VERSION_MAJOR, <PROJECT-NAME>_VERSION_MAJOR
• PROJECT_VERSION_MINOR, <PROJECT-NAME>_VERSION_MINOR
• PROJECT_VERSION_PATCH, <PROJECT-NAME>_VERSION_PATCH
• PROJECT_VERSION_TWEAK, <PROJECT-NAME>_VERSION_TWEAK.
New in version 3.12: When the project() command is called from the top-level CMakeLists.txt, then
the version is also stored in the variable CMAKE_PROJECT_VERSION.
DESCRIPTION <project-description-string>
New in version 3.9.
Optional. Sets the variables
• PROJECT_DESCRIPTION, <PROJECT-NAME>_DESCRIPTION
to <project-description-string>. It is recommended that this description is a relatively short
string, usually no more than a few words.
When the project() command is called from the top-level CMakeLists.txt, then the description is
also stored in the variable CMAKE_PROJECT_DESCRIPTION.
New in version 3.12: Added the <PROJECT-NAME>_DESCRIPTION variable.
HOMEPAGE_URL <url-string>
New in version 3.12.
Optional. Sets the variables
• PROJECT_HOMEPAGE_URL, <PROJECT-NAME>_HOMEPAGE_URL
to <url-string>, which should be the canonical home URL for the project.
When the project() command is called from the top-level CMakeLists.txt, then the URL also is
stored in the variable CMAKE_PROJECT_HOMEPAGE_URL.
LANGUAGES <language-name>...
Optional. Can also be specified without LANGUAGES keyword per the first, short signature.
Selects which programming languages are needed to build the project. Supported languages 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 options are intended for use as
default values in package metadata and documentation.
Code Injection
If the CMAKE_PROJECT_INCLUDE_BEFORE or CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE variables are set, the
files they point to will be included as the first step of the project() command. If both are set, then
CMAKE_PROJECT_INCLUDE_BEFORE will be included before CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE.
If the CMAKE_PROJECT_INCLUDE or CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE variables are set, the files they
point to will be included as the last step of the project() command. If both are set, then
CMAKE_PROJECT_INCLUDE will be included before CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE.
New in version 3.15: Added the CMAKE_PROJECT_INCLUDE and CMAKE_PROJECT_INCLUDE_BEFORE variables.
New in version 3.17: Added the CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE variable.
Usage
The top-level CMakeLists.txt file for a project must contain a literal, direct call to the project()
command; loading one through the include() command is not sufficient. If no such call exists, CMake will
issue a warning and pretend there is a project(Project) at the top to enable the default languages (C and
CXX).
NOTE:
Call the project() command near the top of the top-level CMakeLists.txt, but after calling
cmake_minimum_required(). It is important to establish version and policy settings before invoking
other commands whose behavior they may affect. See also policy CMP0000.
remove_definitions
Remove -D define flags added by add_definitions().
remove_definitions(-DFOO -DBAR ...)
Removes flags (added by add_definitions()) from the compiler command line for sources in the current
directory and below.
set_source_files_properties
Source files can have properties that affect how they are built.
set_source_files_properties(<files> ...
[DIRECTORY <dirs> ...]
[TARGET_DIRECTORY <targets> ...]
PROPERTIES <prop1> <value1>
[<prop2> <value2>] ...)
Sets properties associated with source files using a key/value paired list.
New in version 3.18: By default, source file properties are only visible to targets added in the same
directory (CMakeLists.txt). Visibility can be set in other directory scopes using one or both of the
following options:
DIRECTORY <dirs>...
The source file properties will be set in each of the <dirs> directories' scopes. CMake must
already know about each of these source directories, either by having added them through a call to
add_subdirectory() or it being the top level source directory. Relative paths are treated as
relative to the current source directory.
TARGET_DIRECTORY <targets>...
The source file properties will be set in each of the directory scopes where any of the specified
<targets> were created (the <targets> must therefore already exist).
Use get_source_file_property() to get property values. See also the set_property(SOURCE) command.
See Source File Properties 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 Target Properties 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. Generator
expressions will be expanded the same as supported by the test's add_test() call.
See also the set_property(TEST) command.
See Test Properties for the list of properties known to CMake.
source_group
Define a grouping for source files in IDE project generation. There are two different signatures to
create source groups.
source_group(<name> [FILES <src>...] [REGULAR_EXPRESSION <regex>])
source_group(TREE <root> [PREFIX <prefix>] [FILES <src>...])
Defines a group into which sources will be placed in project files. This is intended to set up file tabs
in Visual Studio. The group is scoped in the directory where the command is called, and applies to
sources in targets created in that directory.
The options are:
TREE New in version 3.8.
CMake will automatically detect, from <src> files paths, source groups it needs to create, to keep
structure of source groups analogically to the actual files and directories structure in the
project. Paths of <src> files will be cut to be relative to <root>. The command fails if the paths
within src do not start with root.
PREFIX New in version 3.8.
Source group and files located directly in <root> path, will be placed in <prefix> source groups.
FILES Any source file specified explicitly will be placed in group <name>. Relative paths are
interpreted with respect to the current source directory.
REGULAR_EXPRESSION
Any source file whose name matches the regular expression will be placed in group <name>.
If a source file matches multiple groups, the last group that explicitly lists the file with FILES will
be favored, if any. If no group explicitly lists the file, the last group whose regular expression
matches the file will be favored.
The <name> of the group and <prefix> argument may contain forward slashes or backslashes to specify
subgroups. Backslashes need to be escaped appropriately:
source_group(base/subdir ...)
source_group(outer\\inner ...)
source_group(TREE <root> PREFIX sources\\inc ...)
New in version 3.18: Allow using forward slashes (/) to specify subgroups.
For backwards compatibility, the short-hand signature
source_group(<name> <regex>)
is equivalent to
source_group(<name> REGULAR_EXPRESSION <regex>)
target_compile_definitions
Add compile definitions to a target.
target_compile_definitions(<target>
<INTERFACE|PUBLIC|PRIVATE> [items1...]
[<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])
Specifies compile definitions to use when compiling a given <target>. The named <target> must have been
created by a command such as add_executable() or add_library() and must not be an ALIAS target.
The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments.
PRIVATE and PUBLIC items will populate the COMPILE_DEFINITIONS property of <target>. PUBLIC and INTERFACE
items will populate the INTERFACE_COMPILE_DEFINITIONS property of <target>. The following arguments
specify compile definitions. Repeated calls for the same <target> append items in the order called.
New in version 3.11: Allow setting INTERFACE items on IMPORTED targets.
Arguments to target_compile_definitions may use "generator expressions" with the syntax $<...>. See the
cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for
more on defining buildsystem properties.
Any leading -D on an item will be removed. Empty items are ignored. For example, the following are all
equivalent:
target_compile_definitions(foo PUBLIC FOO)
target_compile_definitions(foo PUBLIC -DFOO) # -D removed
target_compile_definitions(foo PUBLIC "" FOO) # "" ignored
target_compile_definitions(foo PUBLIC -D FOO) # -D becomes "", then ignored
Definitions may optionally have values:
target_compile_definitions(foo PUBLIC FOO=1)
Note that many compilers treat -DFOO as equivalent to -DFOO=1, but other tools may not recognize this in
all circumstances (e.g. IntelliSense).
target_compile_features
New in version 3.1.
Add expected compiler features to a target.
target_compile_features(<target> <PRIVATE|PUBLIC|INTERFACE> <feature> [...])
Specifies compiler features required when compiling a given target. If the feature is not listed in the
CMAKE_C_COMPILE_FEATURES, CMAKE_CUDA_COMPILE_FEATURES, or CMAKE_CXX_COMPILE_FEATURES variables, then an
error will be reported by CMake. If the use of the feature requires an additional compiler flag, such as
-std=gnu++11, the flag will be added automatically.
The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the features. PRIVATE
and PUBLIC items will populate the COMPILE_FEATURES property of <target>. PUBLIC and INTERFACE items
will populate the INTERFACE_COMPILE_FEATURES property of <target>. Repeated calls for the same <target>
append items.
New in version 3.11: Allow setting INTERFACE items on IMPORTED targets.
The named <target> must have been created by a command such as add_executable() or add_library() and must
not be an ALIAS target.
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 populate the COMPILE_OPTIONS property of <target>. PUBLIC and INTERFACE
items will populate the INTERFACE_COMPILE_OPTIONS property of <target>. The following arguments specify
compile options. Repeated calls for the same <target> append items in the order called.
New in version 3.11: Allow setting INTERFACE items on IMPORTED targets.
Arguments to target_compile_options may use "generator expressions" with the syntax $<...>. See the
cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for
more on defining buildsystem properties.
Option De-duplication
The final set of options used for a target is constructed by accumulating options from the current target
and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.
New in version 3.12: While beneficial for individual options, the de-duplication step can break up option
groups. For example, -option A -option B becomes -option A B. One may specify a group of options using
shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option
string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A"
"SHELL:-option B" becomes -option A -option B.
See Also
This command can be used to add any options. However, for adding preprocessor definitions and include
directories it is recommended to use the more specific commands target_compile_definitions() and
target_include_directories().
For directory-wide settings, there is the command add_compile_options().
For file-specific settings, there is the source file property COMPILE_OPTIONS.
target_include_directories
Add include directories to a target.
target_include_directories(<target> [SYSTEM] [AFTER|BEFORE]
<INTERFACE|PUBLIC|PRIVATE> [items1...]
[<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])
Specifies include directories to use when compiling a given target. The named <target> must have been
created by a command such as add_executable() or add_library() and must not be an ALIAS target.
By using AFTER or BEFORE explicitly, you can select between appending and prepending, independent of the
default.
The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments.
PRIVATE and PUBLIC items will populate the INCLUDE_DIRECTORIES property of <target>. PUBLIC and
INTERFACE items will populate the INTERFACE_INCLUDE_DIRECTORIES property of <target>. The following
arguments specify include directories.
New in version 3.11: Allow setting INTERFACE items on IMPORTED targets.
Specified include directories may be absolute paths or relative paths. 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 (signalling this setting might
achieve effects such as the compiler skipping warnings, or these fixed-install system files not being
considered in dependency calculations - see compiler docs). 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.
Include directories usage requirements commonly differ between the build-tree and the install-tree. The
BUILD_INTERFACE and INSTALL_INTERFACE generator expressions can be used to describe separate usage
requirements based on the usage location. Relative paths are allowed within the INSTALL_INTERFACE
expression and are interpreted relative to the installation prefix. For example:
target_include_directories(mylib PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/mylib>
$<INSTALL_INTERFACE:include/mylib> # <prefix>/include/mylib
)
Creating Relocatable Packages
Note that it is not advisable to populate the INSTALL_INTERFACE of the INTERFACE_INCLUDE_DIRECTORIES of a
target with absolute paths to the include directories of dependencies. That would hard-code into
installed packages the include directory paths for dependencies as found on the machine the package was
made on.
The INSTALL_INTERFACE of the INTERFACE_INCLUDE_DIRECTORIES is only suitable for specifying the required
include directories for headers provided with the target itself, not those provided by the transitive
dependencies listed in its INTERFACE_LINK_LIBRARIES target property. Those dependencies should
themselves be targets that specify their own header locations in INTERFACE_INCLUDE_DIRECTORIES.
See the Creating Relocatable Packages section of the cmake-packages(7) manual for discussion of
additional care that must be taken when specifying usage requirements while creating packages for
redistribution.
target_link_directories
New in version 3.13.
Add link directories to a target.
target_link_directories(<target> [BEFORE]
<INTERFACE|PUBLIC|PRIVATE> [items1...]
[<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])
Specifies the paths in which the linker should search for libraries when linking a given target. Each
item can be an absolute or relative path, with the latter being interpreted as relative to the current
source directory. These items will be added to the link command.
The named <target> must have been created by a command such as add_executable() or add_library() and must
not be an ALIAS target.
The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the items that follow
them. PRIVATE and PUBLIC items will populate the LINK_DIRECTORIES property of <target>. PUBLIC and
INTERFACE items will populate the INTERFACE_LINK_DIRECTORIES property of <target> (IMPORTED targets only
support INTERFACE items). Each item specifies a link directory and will be converted to an absolute path
if necessary before adding it to the relevant property. Repeated calls for the same <target> append
items in the order called.
If BEFORE is specified, the content will be prepended to the relevant property instead of being appended.
Arguments to target_link_directories may use "generator expressions" with the syntax $<...>. See the
cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for
more on defining buildsystem properties.
NOTE:
This command is rarely necessary and should be avoided where there are other choices. Prefer to pass
full absolute paths to libraries where possible, since this ensures the correct library will always be
linked. The find_library() command provides the full path, which can generally be used directly in
calls to target_link_libraries(). Situations where a library search path may be needed include:
• Project generators like Xcode where the user can switch target architecture at build time, but a
full path to a library cannot be used because it only provides one architecture (i.e. it is not a
universal binary).
• Libraries may themselves have other private library dependencies that expect to be found via RPATH
mechanisms, but some linkers are not able to fully decode those paths (e.g. due to the presence of
things like $ORIGIN).
target_link_libraries
Specify libraries or flags to use when linking a given target and/or its dependents. Usage requirements
from linked library targets will be propagated. Usage requirements of a target's dependencies affect
compilation of its own sources.
Overview
This command has several signatures as detailed in subsections below. All of them have the general form
target_link_libraries(<target> ... <item>... ...)
The named <target> must have been created by a command such as add_executable() or add_library() and must
not be an ALIAS target. If policy CMP0079 is not set to NEW then the target must have been created in
the current directory. Repeated calls for the same <target> append items in the order called.
New in version 3.13: The <target> doesn't have to be defined in the same directory as the
target_link_libraries call.
Each <item> may be:
• A library target name: The generated link line will have the full path to the linkable library file
associated with the target. The buildsystem will have a dependency to re-link <target> if the library
file changes.
The named target must be created by add_library() within the project or as an IMPORTED library. If it
is created within the project an ordering dependency will automatically be added in the build system to
make sure the named library target is up-to-date before the <target> links.
If an imported library has the IMPORTED_NO_SONAME target property set, CMake may ask the linker to
search for the library instead of using the full path (e.g. /usr/lib/libfoo.so becomes -lfoo).
The full path to the target's artifact will be quoted/escaped for the shell automatically.
• A full path to a library file: The generated link line will normally preserve the full path to the
file. The buildsystem will have a dependency to re-link <target> if the library file changes.
There are some cases where CMake may ask the linker to search for the library (e.g. /usr/lib/libfoo.so
becomes -lfoo), such as when a shared library is detected to have no SONAME field. See policy CMP0060
for discussion of another case.
If the library file is in a macOS framework, the Headers directory of the framework will also be
processed as a usage requirement. This has the same effect as passing the framework directory as an
include directory.
New in version 3.8: On Visual Studio Generators for VS 2010 and above, library files ending in .targets
will be treated as MSBuild targets files and imported into generated project files. This is not
supported by other generators.
The full path to the library file will be quoted/escaped for the shell automatically.
• A plain library name: The generated link line will ask the linker to search for the library (e.g. foo
becomes -lfoo or foo.lib).
The library name/flag is treated as a command-line string fragment and will be used with no extra
quoting or escaping.
• A link flag: Item names starting with -, but not -l or -framework, are treated as linker flags. Note
that such flags will be treated like any other library link item for purposes of transitive
dependencies, so they are generally safe to specify only as private link items that will not propagate
to dependents.
Link flags specified here are inserted into the link command in the same place as the link libraries.
This might not be correct, depending on the linker. Use the LINK_OPTIONS target property or
target_link_options() command to add link flags explicitly. The flags will then be placed at the
toolchain-defined flag position in the link command.
New in version 3.13: LINK_OPTIONS target property and target_link_options() command. For earlier
versions of CMake, use LINK_FLAGS property instead.
The link flag is treated as a command-line string fragment and will be used with no extra quoting or
escaping.
• A generator expression: A $<...> generator expression may evaluate to any of the above items or to a
semicolon-separated list of them. If the ... contains any ; characters, e.g. after evaluation of a
${list} variable, be sure to use an explicitly quoted argument "$<...>" so that this command receives
it as a single <item>.
Additionally, a generator expression may be used as a fragment of any of the above items, e.g.
foo$<1:_d>.
Note that generator expressions will not be used in OLD handling of policy CMP0003 or policy CMP0004.
• A debug, optimized, or general keyword immediately followed by another <item>. The item following such
a keyword will be used only for the corresponding build configuration. The debug keyword corresponds
to the Debug configuration (or to configurations named in the DEBUG_CONFIGURATIONS global property if
it is set). The optimized keyword corresponds to all other configurations. The general keyword
corresponds to all configurations, and is purely optional. Higher granularity may be achieved for
per-configuration rules by creating and linking to IMPORTED library targets. These keywords are
interpreted immediately by this command and therefore have no special meaning when produced by a
generator expression.
Items containing ::, such as Foo::Bar, are assumed to be IMPORTED or ALIAS library target names and will
cause an error if no such target exists. See policy CMP0028.
See the cmake-buildsystem(7) manual for more on defining buildsystem properties.
Libraries for a Target and/or its Dependents
target_link_libraries(<target>
<PRIVATE|PUBLIC|INTERFACE> <item>...
[<PRIVATE|PUBLIC|INTERFACE> <item>...]...)
The PUBLIC, PRIVATE and INTERFACE keywords can be used to specify both the link dependencies and the link
interface in one command. Libraries and targets following PUBLIC are linked to, and are made part of the
link interface. Libraries and targets following PRIVATE are linked to, but are not made part of the link
interface. Libraries following INTERFACE are appended to the link interface and are not used for linking
<target>.
Libraries for both a Target and its Dependents
target_link_libraries(<target> <item>...)
Library dependencies are transitive by default with this signature. When this target is linked into
another target then the libraries linked to this target will appear on the link line for the other target
too. This transitive "link interface" is stored in the INTERFACE_LINK_LIBRARIES target property and may
be overridden by setting the property directly. When CMP0022 is not set to NEW, transitive linking is
built in but may be overridden by the LINK_INTERFACE_LIBRARIES property. Calls to other signatures of
this command may set the property making any libraries linked exclusively by this signature private.
Libraries for a Target and/or its Dependents (Legacy)
target_link_libraries(<target>
<LINK_PRIVATE|LINK_PUBLIC> <lib>...
[<LINK_PRIVATE|LINK_PUBLIC> <lib>...]...)
The LINK_PUBLIC and LINK_PRIVATE modes can be used to specify both the link dependencies and the link
interface in one command.
This signature is for compatibility only. Prefer the PUBLIC or PRIVATE keywords instead.
Libraries and targets following LINK_PUBLIC are linked to, and are made part of the
INTERFACE_LINK_LIBRARIES. If policy CMP0022 is not NEW, they are also made part of the
LINK_INTERFACE_LIBRARIES. Libraries and targets following LINK_PRIVATE are linked to, but are not made
part of the INTERFACE_LINK_LIBRARIES (or LINK_INTERFACE_LIBRARIES).
Libraries for Dependents Only (Legacy)
target_link_libraries(<target> LINK_INTERFACE_LIBRARIES <item>...)
The LINK_INTERFACE_LIBRARIES mode appends the libraries to the INTERFACE_LINK_LIBRARIES target property
instead of using them for linking. If policy CMP0022 is not NEW, then this mode also appends libraries
to the LINK_INTERFACE_LIBRARIES and its per-configuration equivalent.
This signature is for compatibility only. Prefer the INTERFACE mode instead.
Libraries specified as debug are wrapped in a generator expression to correspond to debug builds. If
policy CMP0022 is not NEW, the libraries are also appended to the LINK_INTERFACE_LIBRARIES_DEBUG property
(or to the properties corresponding to configurations listed in the DEBUG_CONFIGURATIONS global property
if it is set). Libraries specified as optimized are appended to the INTERFACE_LINK_LIBRARIES property.
If policy CMP0022 is not NEW, they are also appended to the LINK_INTERFACE_LIBRARIES property. Libraries
specified as general (or without any keyword) are treated as if specified for both debug and optimized.
Linking Object Libraries
New in version 3.12.
Object Libraries may be used as the <target> (first) argument of target_link_libraries to specify
dependencies of their sources on other libraries. For example, the code
add_library(A SHARED a.c)
target_compile_definitions(A PUBLIC A)
add_library(obj OBJECT obj.c)
target_compile_definitions(obj PUBLIC OBJ)
target_link_libraries(obj PUBLIC A)
compiles obj.c with -DA -DOBJ and establishes usage requirements for obj that propagate to its
dependents.
Normal libraries and executables may link to Object Libraries to get their objects and usage
requirements. Continuing the above example, the code
add_library(B SHARED b.c)
target_link_libraries(B PUBLIC obj)
compiles b.c with -DA -DOBJ, creates shared library B with object files from b.c and obj.c, and links B
to A. Furthermore, the code
add_executable(main main.c)
target_link_libraries(main B)
compiles main.c with -DA -DOBJ and links executable main to B and A. The object library's usage
requirements are propagated transitively through B, but its object files are not.
Object Libraries may "link" to other object libraries to get usage requirements, but since they do not
have a link step nothing is done with their object files. Continuing from the above example, the code:
add_library(obj2 OBJECT obj2.c)
target_link_libraries(obj2 PUBLIC obj)
add_executable(main2 main2.c)
target_link_libraries(main2 obj2)
compiles obj2.c with -DA -DOBJ, creates executable main2 with object files from main2.c and obj2.c, and
links main2 to A.
In other words, when Object Libraries appear in a target's INTERFACE_LINK_LIBRARIES property they will be
treated as Interface Libraries, but when they appear in a target's LINK_LIBRARIES property their object
files will be included in the link too.
Linking Object Libraries via $<TARGET_OBJECTS>
New in version 3.21.
The object files associated with an object library may be referenced by the $<TARGET_OBJECTS> generator
expression. Such object files are placed on the link line before all libraries, regardless of their
relative order. Additionally, an ordering dependency will be added to the build system to make sure the
object library is up-to-date before the dependent target links. For example, the code
add_library(obj3 OBJECT obj3.c)
target_compile_definitions(obj3 PUBLIC OBJ3)
add_executable(main3 main3.c)
target_link_libraries(main3 PRIVATE a3 $<TARGET_OBJECTS:obj3> b3)
links executable main3 with object files from main3.c and obj3.c followed by the a3 and b3 libraries.
main3.c is not compiled with usage requirements from obj3, such as -DOBJ3.
This approach can be used to achieve transitive inclusion of object files in link lines as usage
requirements. Continuing the above example, the code
add_library(iface_obj3 INTERFACE)
target_link_libraries(iface_obj3 INTERFACE obj3 $<TARGET_OBJECTS:obj3>)
creates an interface library iface_obj3 that forwards the obj3 usage requirements and adds the obj3
object files to dependents' link lines. The code
add_executable(use_obj3 use_obj3.c)
target_link_libraries(use_obj3 PRIVATE iface_obj3)
compiles use_obj3.c with -DOBJ3 and links executable use_obj3 with object files from use_obj3.c and
obj3.c.
This also works transitively through a static library. Since a static library does not link, it does not
consume the object files from object libraries referenced this way. Instead, the object files become
transitive link dependencies of the static library. Continuing the above example, the code
add_library(static3 STATIC static3.c)
target_link_libraries(static3 PRIVATE iface_obj3)
add_executable(use_static3 use_static3.c)
target_link_libraries(use_static3 PRIVATE static3)
compiles static3.c with -DOBJ3 and creates libstatic3.a using only its own object file. use_static3.c is
compiled without -DOBJ3 because the usage requirement is not transitive through the private dependency of
static3. However, the link dependencies of static3 are propagated, including the iface_obj3 reference to
$<TARGET_OBJECTS:obj3>. The use_static3 executable is created with object files from use_static3.c and
obj3.c, and linked to library libstatic3.a.
When using this approach, it is the project's responsibility to avoid linking multiple dependent binaries
to iface_obj3, because they will all get the obj3 object files on their link lines.
NOTE:
Referencing $<TARGET_OBJECTS> in target_link_libraries calls worked in versions of CMake prior to 3.21
for some cases, but was not fully supported:
• It did not place the object files before libraries on link lines.
• It did not add an ordering dependency on the object library.
• It did not work in Xcode with multiple architectures.
Cyclic Dependencies of Static Libraries
The library dependency graph is normally acyclic (a DAG), but in the case of mutually-dependent STATIC
libraries CMake allows the graph to contain cycles (strongly connected components). When another target
links to one of the libraries, CMake repeats the entire connected component. For example, the code
add_library(A STATIC a.c)
add_library(B STATIC b.c)
target_link_libraries(A B)
target_link_libraries(B A)
add_executable(main main.c)
target_link_libraries(main A)
links main to A B A B. While one repetition is usually sufficient, pathological object file and symbol
arrangements can require more. One may handle such cases by using the LINK_INTERFACE_MULTIPLICITY target
property or by manually repeating the component in the last target_link_libraries call. However, if two
archives are really so interdependent they should probably be combined into a single archive, perhaps by
using Object Libraries.
Creating Relocatable Packages
Note that it is not advisable to populate the INTERFACE_LINK_LIBRARIES of a target with absolute paths to
dependencies. That would hard-code into installed packages the library file paths for dependencies as
found on the machine the package was made on.
See the Creating Relocatable Packages section of the cmake-packages(7) manual for discussion of
additional care that must be taken when specifying usage requirements while creating packages for
redistribution.
target_link_options
New in version 3.13.
Add options to the link step for an executable, shared library or module library target.
target_link_options(<target> [BEFORE]
<INTERFACE|PUBLIC|PRIVATE> [items1...]
[<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])
The named <target> must have been created by a command such as add_executable() or add_library() and must
not be an ALIAS target.
This command can be used to add any link options, but alternative commands exist to add libraries
(target_link_libraries() or link_libraries()). See documentation of the directory and target
LINK_OPTIONS properties.
NOTE:
This command cannot be used to add options for static library targets, since they do not use a linker.
To add archiver or MSVC librarian flags, see the STATIC_LIBRARY_OPTIONS target property.
If BEFORE is specified, the content will be prepended to the property instead of being appended.
The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments.
PRIVATE and PUBLIC items will populate the LINK_OPTIONS property of <target>. PUBLIC and INTERFACE items
will populate the INTERFACE_LINK_OPTIONS property of <target>. The following arguments specify link
options. Repeated calls for the same <target> append items in the order called.
NOTE:
IMPORTED targets only support INTERFACE items.
Arguments to target_link_options may use "generator expressions" with the syntax $<...>. See the
cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for
more on defining buildsystem properties.
Host And Device Specific Link Options
New in version 3.18: When a device link step is involved, which is controlled by
CUDA_SEPARABLE_COMPILATION and CUDA_RESOLVE_DEVICE_SYMBOLS properties and policy CMP0105, the raw options
will be delivered to the host and device link steps (wrapped in -Xcompiler or equivalent for device
link). Options wrapped with $<DEVICE_LINK:...> generator expression will be used only for the device link
step. Options wrapped with $<HOST_LINK:...> generator expression will be used only for the host link
step.
Option De-duplication
The final set of options used for a target is constructed by accumulating options from the current target
and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.
New in version 3.12: While beneficial for individual options, the de-duplication step can break up option
groups. For example, -option A -option B becomes -option A B. One may specify a group of options using
shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped, and the rest of the option
string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-option A"
"SHELL:-option B" becomes -option A -option B.
Handling Compiler Driver Differences
To pass options to the linker tool, each compiler driver has its own syntax. The LINKER: prefix and ,
separator can be used to specify, in a portable way, options to pass to the linker tool. LINKER: is
replaced by the appropriate driver option and , by the appropriate driver separator. The driver prefix
and driver separator are given by the values of the CMAKE_<LANG>_LINKER_WRAPPER_FLAG and
CMAKE_<LANG>_LINKER_WRAPPER_FLAG_SEP variables.
For example, "LINKER:-z,defs" becomes -Xlinker -z -Xlinker defs for Clang and -Wl,-z,defs for GNU GCC.
The LINKER: prefix can be specified as part of a SHELL: prefix expression.
The LINKER: prefix supports, as an alternative syntax, specification of arguments using the SHELL: prefix
and space as separator. The previous example then becomes "LINKER:SHELL:-z defs".
NOTE:
Specifying the SHELL: prefix anywhere other than at the beginning of the LINKER: prefix is not
supported.
target_precompile_headers
New in version 3.16.
Add a list of header files to precompile.
Precompiling header files can speed up compilation by creating a partially processed version of some
header files, and then using that version during compilations rather than repeatedly parsing the original
headers.
Main Form
target_precompile_headers(<target>
<INTERFACE|PUBLIC|PRIVATE> [header1...]
[<INTERFACE|PUBLIC|PRIVATE> [header2...] ...])
The command adds header files to the PRECOMPILE_HEADERS and/or INTERFACE_PRECOMPILE_HEADERS target
properties of <target>. The named <target> must have been created by a command such as add_executable()
or add_library() and must not be an ALIAS target.
The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments.
PRIVATE and PUBLIC items will populate the PRECOMPILE_HEADERS property of <target>. PUBLIC and INTERFACE
items will populate the INTERFACE_PRECOMPILE_HEADERS property of <target> (IMPORTED targets only support
INTERFACE items). Repeated calls for the same <target> will append items in the order called.
Projects should generally avoid using PUBLIC or INTERFACE for targets that will be exported, or they
should at least use the $<BUILD_INTERFACE:...> generator expression to prevent precompile headers from
appearing in an installed exported target. Consumers of a target should typically be in control of what
precompile headers they use, not have precompile headers forced on them by the targets being consumed
(since precompile headers are not typically usage requirements). A notable exception to this is where an
interface library is created to define a commonly used set of precompile headers in one place and then
other targets link to that interface library privately. In this case, the interface library exists
specifically to propagate the precompile headers to its consumers and the consumer is effectively still
in control, since it decides whether to link to the interface library or not.
The list of header files is used to generate a header file named cmake_pch.h|xx which is used to generate
the precompiled header file (.pch, .gch, .pchi) artifact. The cmake_pch.h|xx header file will be force
included (-include for GCC, /FI for MSVC) to all source files, so sources do not need to have #include
"pch.h".
Header file names specified with angle brackets (e.g. <unordered_map>) or explicit double quotes (escaped
for the cmake-language(7), e.g. [["other_header.h"]]) will be treated as is, and include directories must
be available for the compiler to find them. Other header file names (e.g. project_header.h) are
interpreted as being relative to the current source directory (e.g. CMAKE_CURRENT_SOURCE_DIR) and will be
included by absolute path. For example:
target_precompile_headers(myTarget
PUBLIC
project_header.h
PRIVATE
[["other_header.h"]]
<unordered_map>
)
Arguments to target_precompile_headers() may use "generator expressions" with the syntax $<...>. See the
cmake-generator-expressions(7) manual for available expressions. The $<COMPILE_LANGUAGE:...> generator
expression is particularly useful for specifying a language-specific header to precompile for only one
language (e.g. CXX and not C). In this case, header file names that are not explicitly in double quotes
or angle brackets must be specified by absolute path. Also, when specifying angle brackets inside a
generator expression, be sure to encode the closing > as $<ANGLE-R>. For example:
target_precompile_headers(mylib PRIVATE
"$<$<COMPILE_LANGUAGE:CXX>:${CMAKE_CURRENT_SOURCE_DIR}/cxx_only.h>"
"$<$<COMPILE_LANGUAGE:C>:<stddef.h$<ANGLE-R>>"
"$<$<COMPILE_LANGUAGE:CXX>:<cstddef$<ANGLE-R>>"
)
Reusing Precompile Headers
The command also supports a second signature which can be used to specify that one target re-uses a
precompiled header file artifact from another target instead of generating its own:
target_precompile_headers(<target> REUSE_FROM <other_target>)
This form sets the PRECOMPILE_HEADERS_REUSE_FROM property to <other_target> and adds a dependency such
that <target> will depend on <other_target>. CMake will halt with an error if the PRECOMPILE_HEADERS
property of <target> is already set when the REUSE_FROM form is used.
NOTE:
The REUSE_FROM form requires the same set of compiler options, compiler flags and compiler definitions
for both <target> and <other_target>. Some compilers (e.g. GCC) may issue a warning if the
precompiled header file cannot be used (-Winvalid-pch).
See Also
To disable precompile headers for specific targets, see the DISABLE_PRECOMPILE_HEADERS target property.
To prevent precompile headers from being used when compiling a specific source file, see the
SKIP_PRECOMPILE_HEADERS source file property.
target_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.
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.
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 items following 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. The following arguments specify sources. Repeated calls for
the same <target> append items in the order called. The targets created by add_custom_target() can only
have PRIVATE scope.
New in version 3.3: Allow exporting targets with INTERFACE_SOURCES.
New in version 3.11: Allow setting INTERFACE items on IMPORTED targets.
Arguments to target_sources 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.
try_compile
Try building some code.
Try Compiling Whole Projects
try_compile(<resultVar> <bindir> <srcdir>
<projectName> [<targetName>] [CMAKE_FLAGS <flags>...]
[OUTPUT_VARIABLE <var>])
Try building a project. The success or failure of the try_compile, i.e. TRUE or FALSE respectively, is
returned in <resultVar>.
New in version 3.14: The name of the <resultVar> is defined by the user. Previously, it had a fixed name
RESULT_VAR.
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.
Try Compiling Source Files
try_compile(<resultVar> <bindir> <srcfile|SOURCES srcfile...>
[CMAKE_FLAGS <flags>...]
[COMPILE_DEFINITIONS <defs>...]
[LINK_OPTIONS <options>...]
[LINK_LIBRARIES <libs>...]
[OUTPUT_VARIABLE <var>]
[COPY_FILE <fileName> [COPY_FILE_ERROR <var>]]
[<LANG>_STANDARD <std>]
[<LANG>_STANDARD_REQUIRED <bool>]
[<LANG>_EXTENSIONS <bool>]
)
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>.
New in version 3.14: The name of the <resultVar> is defined by the user. Previously, it had a fixed name
RESULT_VAR.
In this form, one or more source files must be provided. If CMAKE_TRY_COMPILE_TARGET_TYPE is unset or is
set to EXECUTABLE, the sources must include a definition for main and CMake will create a CMakeLists.txt
file to build the source(s) as an executable. If CMAKE_TRY_COMPILE_TARGET_TYPE is set to STATIC_LIBRARY,
a static library will be built instead and no definition for main is required. For an executable, the
generated CMakeLists.txt file would contain something like the following:
add_definitions(<expanded COMPILE_DEFINITIONS from caller>)
include_directories(${INCLUDE_DIRECTORIES})
link_directories(${LINK_DIRECTORIES})
add_executable(cmTryCompileExec <srcfile>...)
target_link_options(cmTryCompileExec PRIVATE <LINK_OPTIONS from caller>)
target_link_libraries(cmTryCompileExec ${LINK_LIBRARIES})
The options are:
CMAKE_FLAGS <flags>...
Specify flags of the form -DVAR:TYPE=VALUE to be passed to the cmake command-line used to drive
the test build. The above example shows how values for variables INCLUDE_DIRECTORIES,
LINK_DIRECTORIES, and LINK_LIBRARIES are used.
COMPILE_DEFINITIONS <defs>...
Specify -Ddefinition arguments to pass to add_definitions() in the generated test project.
COPY_FILE <fileName>
Copy the built executable or static library to the given <fileName>.
COPY_FILE_ERROR <var>
Use after COPY_FILE to capture into variable <var> any error message encountered while trying to
copy the file.
LINK_LIBRARIES <libs>...
Specify libraries to be linked in the generated project. The list of libraries may refer to
system libraries and to Imported Targets from the calling project.
If this option is specified, any -DLINK_LIBRARIES=... value given to the CMAKE_FLAGS option will
be ignored.
LINK_OPTIONS <options>...
New in version 3.14.
Specify link step options to pass to target_link_options() or to set the STATIC_LIBRARY_OPTIONS
target property in the generated project, depending on the CMAKE_TRY_COMPILE_TARGET_TYPE variable.
OUTPUT_VARIABLE <var>
Store the output from the build process in the given variable.
<LANG>_STANDARD <std>
New in version 3.8.
Specify the C_STANDARD, CXX_STANDARD, OBJC_STANDARD, OBJCXX_STANDARD, or CUDA_STANDARD target
property of the generated project.
<LANG>_STANDARD_REQUIRED <bool>
New in version 3.8.
Specify the C_STANDARD_REQUIRED, CXX_STANDARD_REQUIRED, OBJC_STANDARD_REQUIRED,
OBJCXX_STANDARD_REQUIRED,or CUDA_STANDARD_REQUIRED target property of the generated project.
<LANG>_EXTENSIONS <bool>
New in version 3.8.
Specify the C_EXTENSIONS, CXX_EXTENSIONS, OBJC_EXTENSIONS, OBJCXX_EXTENSIONS, or CUDA_EXTENSIONS
target property of the generated project.
In this version all files in <bindir>/CMakeFiles/CMakeTmp will be cleaned automatically. For debugging,
--debug-trycompile can be passed to cmake to avoid this clean. However, multiple sequential try_compile
operations reuse this single output directory. If you use --debug-trycompile, you can only debug one
try_compile call at a time. The recommended procedure is to protect all try_compile calls in your
project by if(NOT DEFINED <resultVar>) logic, configure with cmake all the way through once, then delete
the cache entry associated with the try_compile call of interest, and then re-run cmake again with
--debug-trycompile.
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
If CMP0056 is set to NEW, then CMAKE_EXE_LINKER_FLAGS is passed in as well.
Changed in version 3.14: If CMP0083 is set to NEW, then in order to obtain correct behavior at link time,
the check_pie_supported() command from the CheckPIESupported module must be called before using the
try_compile() command.
The current settings of CMP0065 and CMP0083 are propagated through to the generated test project.
Set the CMAKE_TRY_COMPILE_CONFIGURATION variable to choose a build configuration.
New in version 3.6: Set the CMAKE_TRY_COMPILE_TARGET_TYPE variable to specify the type of target used for
the source file signature.
New in version 3.6: Set the CMAKE_TRY_COMPILE_PLATFORM_VARIABLES variable to specify variables that must
be propagated into the test project. This variable is meant for use only in toolchain files and is only
honored by the try_compile() command for the source files form, not when given a whole project.
Changed in version 3.8: If CMP0067 is set to NEW, or any of the <LANG>_STANDARD,
<LANG>_STANDARD_REQUIRED, or <LANG>_EXTENSIONS options are used, then the language standard variables are
honored:
• CMAKE_C_STANDARD
• CMAKE_C_STANDARD_REQUIRED
• CMAKE_C_EXTENSIONS
• CMAKE_CXX_STANDARD
• CMAKE_CXX_STANDARD_REQUIRED
• CMAKE_CXX_EXTENSIONS
• CMAKE_OBJC_STANDARD
• CMAKE_OBJC_STANDARD_REQUIRED
• CMAKE_OBJC_EXTENSIONS
• CMAKE_OBJCXX_STANDARD
• CMAKE_OBJCXX_STANDARD_REQUIRED
• CMAKE_OBJCXX_EXTENSIONS
• CMAKE_CUDA_STANDARD
• CMAKE_CUDA_STANDARD_REQUIRED
• CMAKE_CUDA_EXTENSIONS
Their values are used to set the corresponding target properties in the generated project (unless
overridden by an explicit option).
Changed in version 3.14: For the Green Hills MULTI generator the GHS toolset and target system
customization cache variables are also propagated into the test project.
try_run
Try compiling and then running some code.
Try Compiling and Running Source Files
try_run(<runResultVar> <compileResultVar>
<bindir> <srcfile> [CMAKE_FLAGS <flags>...]
[COMPILE_DEFINITIONS <defs>...]
[LINK_OPTIONS <options>...]
[LINK_LIBRARIES <libs>...]
[COMPILE_OUTPUT_VARIABLE <var>]
[RUN_OUTPUT_VARIABLE <var>]
[OUTPUT_VARIABLE <var>]
[WORKING_DIRECTORY <var>]
[ARGS <args>...])
Try compiling a <srcfile>. Returns TRUE or FALSE for success or failure in <compileResultVar>. If the
compile succeeded, runs the executable 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 information on how the test project is constructed to build the source file.
New in version 3.14: The names of the result variables <runResultVar> and <compileResultVar> are defined
by the user. Previously, they had fixed names RUN_RESULT_VAR and COMPILE_RESULT_VAR.
The options are:
CMAKE_FLAGS <flags>...
Specify flags of the form -DVAR:TYPE=VALUE to be passed to the cmake command-line used to drive
the test build. The example in try_compile() 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.
COMPILE_OUTPUT_VARIABLE <var>
Report the compile step build output in a given variable.
LINK_LIBRARIES <libs>...
New in version 3.2.
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() in the generated project.
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. Prefer COMPILE_OUTPUT_VARIABLE and RUN_OUTPUT_VARIABLE
instead.
RUN_OUTPUT_VARIABLE <var>
Report the output from running the executable in a given variable.
WORKING_DIRECTORY <var>
New in version 3.20.
Run the executable in the given directory. If no WORKING_DIRECTORY is specified, the executable
will run in <bindir>.
Other Behavior Settings
Set the CMAKE_TRY_COMPILE_CONFIGURATION variable to choose a build configuration.
Behavior when Cross Compiling
New in version 3.3: Use CMAKE_CROSSCOMPILING_EMULATOR when running cross-compiled binaries.
When cross compiling, the executable compiled in the first step usually cannot be run on the build host.
The try_run command checks the CMAKE_CROSSCOMPILING variable to detect whether CMake is in
cross-compiling mode. If that is the case, it will still try to compile the executable, but it will not
try to run the executable unless the CMAKE_CROSSCOMPILING_EMULATOR variable is set. Instead it will
create cache variables which must be filled by the user or by presetting them in some CMake script file
to the values the executable would have produced if it had been run on its actual target platform. These
cache entries are:
<runResultVar>
Exit code if the executable were to be run on the target platform.
<runResultVar>__TRYRUN_OUTPUT
Output from stdout and stderr if the executable were to be run on the target platform. This is
created only if the RUN_OUTPUT_VARIABLE or OUTPUT_VARIABLE option was used.
In order to make cross compiling your project easier, use try_run only if really required. If you use
try_run, use the RUN_OUTPUT_VARIABLE or OUTPUT_VARIABLE options only if really required. Using them will
require that when cross-compiling, the cache variables will have to be set manually to the output of the
executable. You can also "guard" the calls to try_run with an if() block checking the
CMAKE_CROSSCOMPILING variable and provide an easy-to-preset alternative for this case.
CTEST COMMANDS
These commands are available only in CTest scripts.
ctest_build
Perform the CTest Build Step as a Dashboard Client.
ctest_build([BUILD <build-dir>] [APPEND]
[CONFIGURATION <config>]
[PARALLEL_LEVEL <parallel>]
[FLAGS <flags>]
[PROJECT_NAME <project-name>]
[TARGET <target-name>]
[NUMBER_ERRORS <num-err-var>]
[NUMBER_WARNINGS <num-warn-var>]
[RETURN_VALUE <result-var>]
[CAPTURE_CMAKE_ERROR <result-var>]
)
Build the project and store results in Build.xml for submission with the ctest_submit() command.
The CTEST_BUILD_COMMAND variable may be set to explicitly specify the build command line. Otherwise the
build command line is computed automatically based on the options given.
The options are:
BUILD <build-dir>
Specify the top-level build directory. If not given, the CTEST_BINARY_DIRECTORY variable is used.
APPEND Mark Build.xml for append to results previously submitted to a dashboard server since the last
ctest_start() call. Append semantics are defined by the dashboard server in use. This does not
cause results to be appended to a .xml file produced by a previous call to this command.
CONFIGURATION <config>
Specify the build configuration (e.g. Debug). If not specified the CTEST_BUILD_CONFIGURATION
variable will be checked. Otherwise the -C <cfg> option given to the ctest(1) command will be
used, if any.
PARALLEL_LEVEL <parallel>
New in version 3.21.
Specify the parallel level of the underlying build system. If not specified, the
CMAKE_BUILD_PARALLEL_LEVEL environment variable will be checked.
FLAGS <flags>
Pass additional arguments to the underlying build command. If not specified the CTEST_BUILD_FLAGS
variable will be checked. This can, e.g., be used to trigger a parallel build using the -j option
of make. See the ProcessorCount module for an example.
PROJECT_NAME <project-name>
Ignored since CMake 3.0.
Changed in version 3.14: This value is no longer required.
TARGET <target-name>
Specify the name of a target to build. If not specified the CTEST_BUILD_TARGET variable will be
checked. Otherwise the default target will be built. This is the "all" target (called ALL_BUILD
in Visual Studio Generators).
NUMBER_ERRORS <num-err-var>
Store the number of build errors detected in the given variable.
NUMBER_WARNINGS <num-warn-var>
Store the number of build warnings detected in the given variable.
RETURN_VALUE <result-var>
Store the return value of the native build tool in the given variable.
CAPTURE_CMAKE_ERROR <result-var>
New in version 3.7.
Store in the <result-var> variable -1 if there are any errors running the command and prevent
ctest from returning non-zero if an error occurs.
QUIET New in version 3.3.
Suppress any CTest-specific non-error output that would have been printed to the console
otherwise. The summary of warnings / errors, as well as the output from the native build tool is
unaffected by this option.
ctest_configure
Perform the CTest Configure Step as a Dashboard Client.
ctest_configure([BUILD <build-dir>] [SOURCE <source-dir>] [APPEND]
[OPTIONS <options>] [RETURN_VALUE <result-var>] [QUIET]
[CAPTURE_CMAKE_ERROR <result-var>])
Configure the project build tree and record results in Configure.xml for submission with the
ctest_submit() command.
The options are:
BUILD <build-dir>
Specify the top-level build directory. If not given, the CTEST_BINARY_DIRECTORY variable is used.
SOURCE <source-dir>
Specify the source directory. If not given, the CTEST_SOURCE_DIRECTORY variable is used.
APPEND Mark Configure.xml for append to results previously submitted to a dashboard server since the last
ctest_start() call. Append semantics are defined by the dashboard server in use. This does not
cause results to be appended to a .xml file produced by a previous call to this command.
OPTIONS <options>
Specify command-line arguments to pass to the configuration tool.
RETURN_VALUE <result-var>
Store in the <result-var> variable the return value of the native configuration tool.
CAPTURE_CMAKE_ERROR <result-var>
New in version 3.7.
Store in the <result-var> variable -1 if there are any errors running the command and prevent
ctest from returning non-zero if an error occurs.
QUIET New in version 3.3.
Suppress any CTest-specific non-error messages that would have otherwise been printed to the
console. Output from the underlying configure command is not affected.
ctest_coverage
Perform the CTest Coverage Step as a Dashboard Client.
ctest_coverage([BUILD <build-dir>] [APPEND]
[LABELS <label>...]
[RETURN_VALUE <result-var>]
[CAPTURE_CMAKE_ERROR <result-var>]
[QUIET]
)
Collect coverage tool results and stores them in Coverage.xml for submission with the ctest_submit()
command.
The options are:
BUILD <build-dir>
Specify the top-level build directory. If not given, the CTEST_BINARY_DIRECTORY variable is used.
APPEND Mark Coverage.xml for append to results previously submitted to a dashboard server since the last
ctest_start() call. Append semantics are defined by the dashboard server in use. This does not
cause results to be appended to a .xml file produced by a previous call to this command.
LABELS Filter the coverage report to include only source files labeled with at least one of the labels
specified.
RETURN_VALUE <result-var>
Store in the <result-var> variable 0 if coverage tools ran without error and non-zero otherwise.
CAPTURE_CMAKE_ERROR <result-var>
New in version 3.7.
Store in the <result-var> variable -1 if there are any errors running the command and prevent
ctest from returning non-zero if an error occurs.
QUIET New in version 3.3.
Suppress any CTest-specific non-error output that would have been printed to the console
otherwise. The summary indicating how many lines of code were covered is unaffected by this
option.
ctest_empty_binary_directory
empties the binary directory
ctest_empty_binary_directory( directory )
Removes a binary directory. This command will perform some checks prior to deleting the directory in an
attempt to avoid malicious or accidental directory deletion.
ctest_memcheck
Perform the CTest MemCheck Step as a Dashboard Client.
ctest_memcheck([BUILD <build-dir>] [APPEND]
[START <start-number>]
[END <end-number>]
[STRIDE <stride-number>]
[EXCLUDE <exclude-regex>]
[INCLUDE <include-regex>]
[EXCLUDE_LABEL <label-exclude-regex>]
[INCLUDE_LABEL <label-include-regex>]
[EXCLUDE_FIXTURE <regex>]
[EXCLUDE_FIXTURE_SETUP <regex>]
[EXCLUDE_FIXTURE_CLEANUP <regex>]
[PARALLEL_LEVEL <level>]
[RESOURCE_SPEC_FILE <file>]
[TEST_LOAD <threshold>]
[SCHEDULE_RANDOM <ON|OFF>]
[STOP_ON_FAILURE]
[STOP_TIME <time-of-day>]
[RETURN_VALUE <result-var>]
[CAPTURE_CMAKE_ERROR <result-var>]
[REPEAT <mode>:<n>]
[OUTPUT_JUNIT <file>]
[DEFECT_COUNT <defect-count-var>]
[QUIET]
)
Run tests with a dynamic analysis tool and store results in MemCheck.xml for submission with the
ctest_submit() command.
Most options are the same as those for the ctest_test() command.
The options unique to this command are:
DEFECT_COUNT <defect-count-var>
New in version 3.8.
Store in the <defect-count-var> the number of defects found.
ctest_read_custom_files
read CTestCustom files.
ctest_read_custom_files( directory ... )
Read all the CTestCustom.ctest or CTestCustom.cmake files from the given directory.
By default, invoking ctest(1) without a script will read custom files from the binary directory.
ctest_run_script
runs a ctest -S script
ctest_run_script([NEW_PROCESS] script_file_name script_file_name1
script_file_name2 ... [RETURN_VALUE var])
Runs a script or scripts much like if it was run from ctest -S. If no argument is provided then the
current script is run using the current settings of the variables. If NEW_PROCESS is specified then each
script will be run in a separate process.If RETURN_VALUE is specified the return value of the last script
run will be put into var.
ctest_sleep
sleeps for some amount of time
ctest_sleep(<seconds>)
Sleep for given number of seconds.
ctest_sleep(<time1> <duration> <time2>)
Sleep for t=(time1 + duration - time2) seconds if t > 0.
ctest_start
Starts the testing for a given model
ctest_start(<model> [<source> [<binary>]] [GROUP <group>] [QUIET])
ctest_start([<model> [<source> [<binary>]]] [GROUP <group>] APPEND [QUIET])
Starts the testing for a given model. The command should be called after the binary directory is
initialized.
The parameters are as follows:
<model>
Set the dashboard model. Must be one of Experimental, Continuous, or Nightly. This parameter is
required unless APPEND is specified.
<source>
Set the source directory. If not specified, the value of CTEST_SOURCE_DIRECTORY is used instead.
<binary>
Set the binary directory. If not specified, the value of CTEST_BINARY_DIRECTORY is used instead.
GROUP <group>
If GROUP is used, the submissions will go to the specified group on the CDash server. If no GROUP
is specified, the name of the model is used by default.
Changed in version 3.16: This replaces the deprecated option TRACK. Despite the name change its
behavior is unchanged.
APPEND If APPEND is used, the existing TAG is used rather than creating a new one based on the current
time stamp. If you use APPEND, you can omit the <model> and GROUP <group> parameters, because they
will be read from the generated TAG file. For example:
ctest_start(Experimental GROUP GroupExperimental)
Later, in another ctest -S script:
ctest_start(APPEND)
When the second script runs ctest_start(APPEND), it will read the Experimental model and
GroupExperimental group from the TAG file generated by the first ctest_start() command. Please
note that if you call ctest_start(APPEND) and specify a different model or group than in the first
ctest_start() command, a warning will be issued, and the new model and group will be used.
QUIET New in version 3.3.
If QUIET is used, CTest will suppress any non-error messages that it otherwise would have printed
to the console.
The parameters for ctest_start() can be issued in any order, with the exception that <model>, <source>,
and <binary> have to appear in that order with respect to each other. The following are all valid and
equivalent:
ctest_start(Experimental path/to/source path/to/binary GROUP SomeGroup QUIET APPEND)
ctest_start(GROUP SomeGroup Experimental QUIET path/to/source APPEND path/to/binary)
ctest_start(APPEND QUIET Experimental path/to/source GROUP SomeGroup path/to/binary)
However, for the sake of readability, it is recommended that you order your parameters in the order
listed at the top of this page.
If the CTEST_CHECKOUT_COMMAND variable (or the CTEST_CVS_CHECKOUT variable) is set, its content is
treated as command-line. The command is invoked with the current working directory set to the parent of
the source directory, even if the source directory already exists. This can be used to create the source
tree from a version control repository.
ctest_submit
Perform the CTest Submit Step as a Dashboard Client.
ctest_submit([PARTS <part>...] [FILES <file>...]
[SUBMIT_URL <url>]
[BUILD_ID <result-var>]
[HTTPHEADER <header>]
[RETRY_COUNT <count>]
[RETRY_DELAY <delay>]
[RETURN_VALUE <result-var>]
[CAPTURE_CMAKE_ERROR <result-var>]
[QUIET]
)
Submit results to a dashboard server. By default all available parts are submitted.
The options are:
PARTS <part>...
Specify a subset of parts to submit. Valid part names are:
Start = nothing
Update = ctest_update results, in Update.xml
Configure = ctest_configure results, in Configure.xml
Build = ctest_build results, in Build.xml
Test = ctest_test results, in Test.xml
Coverage = ctest_coverage results, in Coverage.xml
MemCheck = ctest_memcheck results, in DynamicAnalysis.xml and
DynamicAnalysis-Test.xml
Notes = Files listed by CTEST_NOTES_FILES, in Notes.xml
ExtraFiles = Files listed by CTEST_EXTRA_SUBMIT_FILES
Upload = Files prepared for upload by ctest_upload(), in Upload.xml
Submit = nothing
Done = Build is complete, in Done.xml
FILES <file>...
Specify an explicit list of specific files to be submitted. Each individual file must exist at
the time of the call.
SUBMIT_URL <url>
New in version 3.14.
The http or https URL of the dashboard server to send the submission to. If not given, the
CTEST_SUBMIT_URL variable is used.
BUILD_ID <result-var>
New in version 3.15.
Store in the <result-var> variable the ID assigned to this build by CDash.
HTTPHEADER <HTTP-header>
New in version 3.9.
Specify HTTP header to be included in the request to CDash during submission. For example, CDash
can be configured to only accept submissions from authenticated clients. In this case, you should
provide a bearer token in your header:
ctest_submit(HTTPHEADER "Authorization: Bearer <auth-token>")
This suboption can be repeated several times for multiple headers.
RETRY_COUNT <count>
Specify how many times to retry a timed-out submission.
RETRY_DELAY <delay>
Specify how long (in seconds) to wait after a timed-out submission before attempting to re-submit.
RETURN_VALUE <result-var>
Store in the <result-var> variable 0 for success and non-zero on failure.
CAPTURE_CMAKE_ERROR <result-var>
New in version 3.13.
Store in the <result-var> variable -1 if there are any errors running the command and prevent
ctest from returning non-zero if an error occurs.
QUIET New in version 3.3.
Suppress all non-error messages that would have otherwise been printed to the console.
Submit to CDash Upload API
New in version 3.2.
ctest_submit(CDASH_UPLOAD <file> [CDASH_UPLOAD_TYPE <type>]
[SUBMIT_URL <url>]
[BUILD_ID <result-var>]
[HTTPHEADER <header>]
[RETRY_COUNT <count>]
[RETRY_DELAY <delay>]
[RETURN_VALUE <result-var>]
[QUIET])
This second signature is used to upload files to CDash via the CDash file upload API. The API first sends
a request to upload to CDash along with a content hash of the file. If CDash does not already have the
file, then it is uploaded. Along with the file, a CDash type string is specified to tell CDash which
handler to use to process the data.
This signature interprets options in the same way as the first one.
New in version 3.8: Added the RETRY_COUNT, RETRY_DELAY, QUIET options.
New in version 3.9: Added the HTTPHEADER option.
New in version 3.13: Added the RETURN_VALUE option.
New in version 3.14: Added the SUBMIT_URL option.
New in version 3.15: Added the BUILD_ID option.
ctest_test
Perform the CTest Test Step as a Dashboard Client.
ctest_test([BUILD <build-dir>] [APPEND]
[START <start-number>]
[END <end-number>]
[STRIDE <stride-number>]
[EXCLUDE <exclude-regex>]
[INCLUDE <include-regex>]
[EXCLUDE_LABEL <label-exclude-regex>]
[INCLUDE_LABEL <label-include-regex>]
[EXCLUDE_FIXTURE <regex>]
[EXCLUDE_FIXTURE_SETUP <regex>]
[EXCLUDE_FIXTURE_CLEANUP <regex>]
[PARALLEL_LEVEL <level>]
[RESOURCE_SPEC_FILE <file>]
[TEST_LOAD <threshold>]
[SCHEDULE_RANDOM <ON|OFF>]
[STOP_ON_FAILURE]
[STOP_TIME <time-of-day>]
[RETURN_VALUE <result-var>]
[CAPTURE_CMAKE_ERROR <result-var>]
[REPEAT <mode>:<n>]
[OUTPUT_JUNIT <file>]
[QUIET]
)
Run tests in the project build tree and store results in Test.xml for submission with the ctest_submit()
command.
The options are:
BUILD <build-dir>
Specify the top-level build directory. If not given, the CTEST_BINARY_DIRECTORY variable is used.
APPEND Mark Test.xml for append to results previously submitted to a dashboard server since the last
ctest_start() call. Append semantics are defined by the dashboard server in use. This does not
cause results to be appended to a .xml file produced by a previous call to this command.
START <start-number>
Specify the beginning of a range of test numbers.
END <end-number>
Specify the end of a range of test numbers.
STRIDE <stride-number>
Specify the stride by which to step across a range of test numbers.
EXCLUDE <exclude-regex>
Specify a regular expression matching test names to exclude.
INCLUDE <include-regex>
Specify a regular expression matching test names to include. Tests not matching this expression
are excluded.
EXCLUDE_LABEL <label-exclude-regex>
Specify a regular expression matching test labels to exclude.
INCLUDE_LABEL <label-include-regex>
Specify a regular expression matching test labels to include. Tests not matching this expression
are excluded.
EXCLUDE_FIXTURE <regex>
New in version 3.7.
If a test in the set of tests to be executed requires a particular fixture, that fixture's setup
and cleanup tests would normally be added to the test set automatically. This option prevents
adding setup or cleanup tests for fixtures matching the <regex>. Note that all other fixture
behavior is retained, including test dependencies and skipping tests that have fixture setup tests
that fail.
EXCLUDE_FIXTURE_SETUP <regex>
New in version 3.7.
Same as EXCLUDE_FIXTURE except only matching setup tests are excluded.
EXCLUDE_FIXTURE_CLEANUP <regex>
New in version 3.7.
Same as EXCLUDE_FIXTURE except only matching cleanup tests are excluded.
PARALLEL_LEVEL <level>
Specify a positive number representing the number of tests to be run in parallel.
RESOURCE_SPEC_FILE <file>
New in version 3.16.
Specify a resource specification file. See ctest-resource-allocation for more information.
TEST_LOAD <threshold>
New in version 3.4.
While running tests in parallel, try not to start tests when they may cause the CPU load to pass
above a given threshold. If not specified the CTEST_TEST_LOAD variable will be checked, and then
the --test-load command-line argument to ctest(1). See also the TestLoad setting in the CTest
Test Step.
REPEAT <mode>:<n>
New in version 3.17.
Run tests repeatedly based on the given <mode> up to <n> times. The modes are:
UNTIL_FAIL
Require each test to run <n> times without failing in order to pass. This is useful in
finding sporadic failures in test cases.
UNTIL_PASS
Allow each test to run up to <n> times in order to pass. Repeats tests if they fail for
any reason. This is useful in tolerating sporadic failures in test cases.
AFTER_TIMEOUT
Allow each test to run up to <n> times in order to pass. Repeats tests only if they
timeout. This is useful in tolerating sporadic timeouts in test cases on busy machines.
SCHEDULE_RANDOM <ON|OFF>
Launch tests in a random order. This may be useful for detecting implicit test dependencies.
STOP_ON_FAILURE
New in version 3.18.
Stop the execution of the tests once one has failed.
STOP_TIME <time-of-day>
Specify a time of day at which the tests should all stop running.
RETURN_VALUE <result-var>
Store in the <result-var> variable 0 if all tests passed. Store non-zero if anything went wrong.
CAPTURE_CMAKE_ERROR <result-var>
New in version 3.7.
Store in the <result-var> variable -1 if there are any errors running the command and prevent
ctest from returning non-zero if an error occurs.
OUTPUT_JUNIT <file>
New in version 3.21.
Write test results to <file> in JUnit XML format. If <file> is a relative path, it will be placed
in the build directory. If <file> already exists, it will be overwritten. Note that the resulting
JUnit XML file is not uploaded to CDash because it would be redundant with CTest's Test.xml file.
QUIET New in version 3.3.
Suppress any CTest-specific non-error messages that would have otherwise been printed to the
console. Output from the underlying test command is not affected. Summary info detailing the
percentage of passing tests is also unaffected by the QUIET option.
See also the CTEST_CUSTOM_MAXIMUM_PASSED_TEST_OUTPUT_SIZE and
CTEST_CUSTOM_MAXIMUM_FAILED_TEST_OUTPUT_SIZE variables.
Additional Test Measurements
CTest can parse the output of your tests for extra measurements to report to CDash.
When run as a Dashboard Client, CTest will include these custom measurements in the Test.xml file that
gets uploaded to CDash.
Check the CDash test measurement documentation for more information on the types of test measurements
that CDash recognizes.
The following example demonstrates how to output a variety of custom test measurements.
std::cout <<
"<CTestMeasurement type=\"numeric/double\" name=\"score\">28.3</CTestMeasurement>"
<< std::endl;
std::cout <<
"<CTestMeasurement type=\"text/string\" name=\"color\">red</CTestMeasurement>"
<< std::endl;
std::cout <<
"<CTestMeasurement type=\"text/link\" name=\"CMake URL\">https://cmake.org</CTestMeasurement>"
<< std::endl;
std::cout <<
"<CTestMeasurement type=\"text/preformatted\" name=\"Console Output\">" <<
"line 1.\n" <<
" \033[31;1m line 2. Bold red, and indented!\033[0;0ml\n" <<
"line 3. Not bold or indented...\n" <<
"</CTestMeasurement>" << std::endl;
Image Measurements
The following example demonstrates how to upload test images to CDash.
std::cout <<
"<CTestMeasurementFile type=\"image/jpg\" name=\"TestImage\">" <<
"/dir/to/test_img.jpg</CTestMeasurementFile>" << std::endl;
std::cout <<
"<CTestMeasurementFile type=\"image/gif\" name=\"ValidImage\">" <<
"/dir/to/valid_img.gif</CTestMeasurementFile>" << std::endl;
std::cout <<
"<CTestMeasurementFile type=\"image/png\" name=\"AlgoResult\"> <<
"/dir/to/img.png</CTestMeasurementFile>"
<< std::endl;
Images will be displayed together in an interactive comparison mode on CDash if they are provided with
two or more of the following names.
• TestImage
• ValidImage
• BaselineImage
• DifferenceImage2
By convention, TestImage is the image generated by your test, and ValidImage (or BaselineImage) is basis
of comparison used to determine if the test passed or failed.
If another image name is used it will be displayed by CDash as a static image separate from the
interactive comparison UI.
Attached Files
New in version 3.21.
The following example demonstrates how to upload non-image files to CDash.
std::cout <<
"<CTestMeasurementFile type=\"file\" name=\"TestInputData1\">" <<
"/dir/to/data1.csv</CTestMeasurementFile>\n" <<
"<CTestMeasurementFile type=\"file\" name=\"TestInputData2\">" <<
"/dir/to/data2.csv</CTestMeasurementFile>" << std::endl;
If the name of the file to upload is known at configure time, you can use the ATTACHED_FILES or
ATTACHED_FILES_ON_FAIL test properties instead.
Custom Details
New in version 3.21.
The following example demonstrates how to specify a custom value for the Test Details field displayed on
CDash.
std::cout <<
"<CTestDetails>My Custom Details Value</CTestDetails>" << std::endl;
Additional Labels
New in version 3.22.
The following example demonstrates how to add additional labels to a test at runtime.
std::cout <<
"<CTestLabel>Custom Label 1</CTestLabel>\n" <<
"<CTestLabel>Custom Label 2</CTestLabel>" << std::endl;
Use the LABELS test property instead for labels that can be determined at configure time.
ctest_update
Perform the CTest Update Step as a Dashboard Client.
ctest_update([SOURCE <source-dir>]
[RETURN_VALUE <result-var>]
[CAPTURE_CMAKE_ERROR <result-var>]
[QUIET])
Update the source tree from version control and record results in Update.xml for submission with the
ctest_submit() command.
The options are:
SOURCE <source-dir>
Specify the source directory. If not given, the CTEST_SOURCE_DIRECTORY variable is used.
RETURN_VALUE <result-var>
Store in the <result-var> variable the number of files updated or -1 on error.
CAPTURE_CMAKE_ERROR <result-var>
New in version 3.13.
Store in the <result-var> variable -1 if there are any errors running the command and prevent
ctest from returning non-zero if an error occurs.
QUIET New in version 3.3.
Tell CTest to suppress most non-error messages that it would have otherwise printed to the
console. CTest will still report the new revision of the repository and any conflicting files
that were found.
The update always follows the version control branch currently checked out in the source directory. See
the CTest Update Step documentation for information about variables that change the behavior of
ctest_update().
ctest_upload
Upload files to a dashboard server as a Dashboard Client.
ctest_upload(FILES <file>... [QUIET] [CAPTURE_CMAKE_ERROR <result-var>])
The options are:
FILES <file>...
Specify a list of files to be sent along with the build results to the dashboard server.
QUIET New in version 3.3.
Suppress any CTest-specific non-error output that would have been printed to the console
otherwise.
CAPTURE_CMAKE_ERROR <result-var>
New in version 3.7.
Store in the <result-var> variable -1 if there are any errors running the command and prevent
ctest from returning non-zero if an error occurs.
DEPRECATED COMMANDS
These commands are deprecated and are only made available to maintain backward compatibility. The
documentation of each command states the CMake version in which it was deprecated. Do not use these
commands in new code.
build_name
Disallowed since version 3.0. See CMake Policy CMP0036.
Use ${CMAKE_SYSTEM} and ${CMAKE_CXX_COMPILER} instead.
build_name(variable)
Sets the specified variable to a string representing the platform and compiler settings. These values
are now available through the CMAKE_SYSTEM and CMAKE_CXX_COMPILER variables.
exec_program
Deprecated since version 3.0: Use the execute_process() command instead.
Run an executable program during the processing of the CMakeList.txt file.
exec_program(Executable [directory in which to run]
[ARGS <arguments to executable>]
[OUTPUT_VARIABLE <var>]
[RETURN_VALUE <var>])
The executable is run in the optionally specified directory. The executable can include arguments if it
is double quoted, but it is better to use the optional ARGS argument to specify arguments to the program.
This is because cmake will then be able to escape spaces in the executable path. An optional argument
OUTPUT_VARIABLE specifies a variable in which to store the output. To capture the return value of the
execution, provide a RETURN_VALUE. If OUTPUT_VARIABLE is specified, then no output will go to the
stdout/stderr of the console running cmake.
export_library_dependencies
Disallowed since version 3.0. See CMake Policy CMP0033.
Use install(EXPORT) or export() command.
This command generates an old-style library dependencies file. Projects requiring CMake 2.6 or later
should not use the command. Use instead the install(EXPORT) command to help export targets from an
installation tree and the export() command to export targets from a build tree.
The old-style library dependencies file does not take into account per-configuration names of libraries
or the LINK_INTERFACE_LIBRARIES target property.
export_library_dependencies(<file> [APPEND])
Create a file named <file> that can be included into a CMake listfile with the INCLUDE command. The file
will contain a number of SET commands that will set all the variables needed for library dependency
information. This should be the last command in the top level CMakeLists.txt file of the project. If
the APPEND option is specified, the SET commands will be appended to the given file instead of replacing
it.
install_files
Deprecated since version 3.0: Use the install(FILES) command instead.
This command has been superseded by the install() command. It is provided for compatibility with older
CMake code. The FILES form is directly replaced by the FILES form of the install() command. The regexp
form can be expressed more clearly using the GLOB form of the file() command.
install_files(<dir> extension file file ...)
Create rules to install the listed files with the given extension into the given directory. Only files
existing in the current source tree or its corresponding location in the binary tree may be listed. If a
file specified already has an extension, that extension will be removed first. This is useful for
providing lists of source files such as foo.cxx when you want the corresponding foo.h to be installed. A
typical extension is .h.
install_files(<dir> regexp)
Any files in the current source directory that match the regular expression will be installed.
install_files(<dir> FILES file file ...)
Any files listed after the FILES keyword will be installed explicitly from the names given. Full paths
are allowed in this form.
The directory <dir> is relative to the installation prefix, which is stored in the variable
CMAKE_INSTALL_PREFIX.
install_programs
Deprecated since version 3.0: Use the install(PROGRAMS) command instead.
This command has been superseded by the install() command. It is provided for compatibility with older
CMake code. The FILES form is directly replaced by the PROGRAMS form of the install() command. The
regexp form can be expressed more clearly using the GLOB form of the file() command.
install_programs(<dir> file1 file2 [file3 ...])
install_programs(<dir> FILES file1 [file2 ...])
Create rules to install the listed programs into the given directory. Use the FILES argument to
guarantee that the file list version of the command will be used even when there is only one argument.
install_programs(<dir> regexp)
In the second form any program in the current source directory that matches the regular expression will
be installed.
This command is intended to install programs that are not built by cmake, such as shell scripts. See the
TARGETS form of the install() command to create installation rules for targets built by cmake.
The directory <dir> is relative to the installation prefix, which is stored in the variable
CMAKE_INSTALL_PREFIX.
install_targets
Deprecated since version 3.0: Use the install(TARGETS) command instead.
This command has been superseded by the install() command. It is provided for compatibility with older
CMake code.
install_targets(<dir> [RUNTIME_DIRECTORY dir] target target)
Create rules to install the listed targets into the given directory. The directory <dir> is relative to
the installation prefix, which is stored in the variable CMAKE_INSTALL_PREFIX. If RUNTIME_DIRECTORY is
specified, then on systems with special runtime files (Windows DLL), the files will be copied to that
directory.
load_command
Disallowed since version 3.0. See CMake Policy CMP0031.
Load a command into a running CMake.
load_command(COMMAND_NAME <loc1> [loc2 ...])
The given locations are searched for a library whose name is cmCOMMAND_NAME. If found, it is loaded as a
module and the command is added to the set of available CMake commands. Usually, try_compile() is used
before this command to compile the module. If the command is successfully loaded a variable named
CMAKE_LOADED_COMMAND_<COMMAND_NAME>
will be set to the full path of the module that was loaded. Otherwise the variable will not be set.
make_directory
Deprecated since version 3.0: Use the file(MAKE_DIRECTORY) command instead.
make_directory(directory)
Creates the specified directory. Full paths should be given. Any parent directories that do not exist
will also be created. Use with care.
output_required_files
Disallowed since version 3.0. See CMake Policy CMP0032.
Approximate C preprocessor dependency scanning.
This command exists only because ancient CMake versions provided it. CMake handles preprocessor
dependency scanning automatically using a more advanced scanner.
output_required_files(srcfile outputfile)
Outputs a list of all the source files that are required by the specified srcfile. This list is written
into outputfile. This is similar to writing out the dependencies for srcfile except that it jumps from
.h files into .cxx, .c and .cpp files if possible.
qt_wrap_cpp
Deprecated since version 3.14: This command was originally added to support Qt 3 before the
add_custom_command() command was sufficiently mature. The FindQt4 module provides the qt4_wrap_cpp()
macro, which should be used instead for Qt 4 projects. For projects using Qt 5 or later, use the
equivalent macro provided by Qt itself (e.g. Qt 5 provides qt5_wrap_cpp()).
Manually create Qt Wrappers.
qt_wrap_cpp(resultingLibraryName DestName SourceLists ...)
Produces moc files for all the .h files listed in the SourceLists. The moc files will be added to the
library using the DestName source list.
Consider updating the project to use the AUTOMOC target property instead for a more automated way of
invoking the moc tool.
qt_wrap_ui
Deprecated since version 3.14: This command was originally added to support Qt 3 before the
add_custom_command() command was sufficiently mature. The FindQt4 module provides the qt4_wrap_ui()
macro, which should be used instead for Qt 4 projects. For projects using Qt 5 or later, use the
equivalent macro provided by Qt itself (e.g. Qt 5 provides qt5_wrap_ui()).
Manually create Qt user interfaces Wrappers.
qt_wrap_ui(resultingLibraryName HeadersDestName
SourcesDestName SourceLists ...)
Produces .h and .cxx files for all the .ui files listed in the SourceLists. The .h files will be added
to the library using the HeadersDestNamesource list. The .cxx files will be added to the library using
the SourcesDestNamesource list.
Consider updating the project to use the AUTOUIC target property instead for a more automated way of
invoking the uic tool.
remove
Deprecated since version 3.0: Use the list(REMOVE_ITEM) command instead.
remove(VAR VALUE VALUE ...)
Removes VALUE from the variable VAR. This is typically used to remove entries from a vector (e.g.
semicolon separated list). VALUE is expanded.
subdir_depends
Disallowed since version 3.0. See CMake Policy CMP0029.
Does nothing.
subdir_depends(subdir dep1 dep2 ...)
Does not do anything. This command used to help projects order parallel builds correctly. This
functionality is now automatic.
subdirs
Deprecated since version 3.0: Use the add_subdirectory() command instead.
Add a list of subdirectories to the build.
subdirs(dir1 dir2 ...[EXCLUDE_FROM_ALL exclude_dir1 exclude_dir2 ...]
[PREORDER] )
Add a list of subdirectories to the build. The add_subdirectory() command should be used instead of
subdirs although subdirs will still work. This will cause any CMakeLists.txt files in the sub
directories to be processed by CMake. Any directories after the PREORDER flag are traversed first by
makefile builds, the PREORDER flag has no effect on IDE projects. Any directories after the
EXCLUDE_FROM_ALL marker will not be included in the top level makefile or project file. This is useful
for having CMake create makefiles or projects for a set of examples in a project. You would want CMake
to generate makefiles or project files for all the examples at the same time, but you would not want them
to show up in the top level project or be built each time make is run from the top.
use_mangled_mesa
Disallowed since version 3.0. See CMake Policy CMP0030.
Copy mesa headers for use in combination with system GL.
use_mangled_mesa(PATH_TO_MESA OUTPUT_DIRECTORY)
The path to mesa includes, should contain gl_mangle.h. The mesa headers are copied to the specified
output directory. This allows mangled mesa headers to override other GL headers by being added to the
include directory path earlier.
utility_source
Disallowed since version 3.0. See CMake Policy CMP0034.
Specify the source tree of a third-party utility.
utility_source(cache_entry executable_name
path_to_source [file1 file2 ...])
When a third-party utility's source is included in the distribution, this command specifies its location
and name. The cache entry will not be set unless the path_to_source and all listed files exist. It is
assumed that the source tree of the utility will have been built before it is needed.
When cross compiling CMake will print a warning if a utility_source() command is executed, because in
many cases it is used to build an executable which is executed later on. This doesn't work when cross
compiling, since the executable can run only on their target platform. So in this case the cache entry
has to be adjusted manually so it points to an executable which is runnable on the build host.
variable_requires
Disallowed since version 3.0. See CMake Policy CMP0035.
Use the if() command instead.
Assert satisfaction of an option's required variables.
variable_requires(TEST_VARIABLE RESULT_VARIABLE
REQUIRED_VARIABLE1
REQUIRED_VARIABLE2 ...)
The first argument (TEST_VARIABLE) is the name of the variable to be tested, if that variable is false
nothing else is done. If TEST_VARIABLE is true, then the next argument (RESULT_VARIABLE) is a variable
that is set to true if all the required variables are set. The rest of the arguments are variables that
must be true or not set to NOTFOUND to avoid an error. If any are not true, an error is reported.
write_file
Deprecated since version 3.0: Use the file(WRITE) command instead.
write_file(filename "message to write"... [APPEND])
The first argument is the file name, the rest of the arguments are messages to write. If the argument
APPEND is specified, then the message will be appended.
NOTE 1: file(WRITE) and file(APPEND) do exactly the same as this one but add some more functionality.
NOTE 2: When using write_file the produced file cannot be used as an input to CMake (CONFIGURE_FILE,
source file ...) because it will lead to an infinite loop. Use configure_file() if you want to generate
input files to CMake.
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