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cmake-generator-expressions(7)

cmake-generator-expressions(7)¶

Contents

cmake-generator-expressions(7)

Introduction

Whitespace And Quoting

Debugging

Generator Expression Reference

Conditional Expressions

Logical Operators

Primary Comparison Expressions

String Comparisons

Version Comparisons

String Transformations

List Expressions

List Comparisons

List Queries

List Transformations

List Ordering

Path Expressions

Path Comparisons

Path Queries

Path Decomposition

Path Transformations

Shell Paths

Configuration Expressions

Toolchain And Language Expressions

Platform

Compiler Version

Compiler Language And ID

Compile Features

Compile Context

Linker Language And ID

Link Features

Link Context

Target-Dependent Expressions

Export And Install Expressions

Multi-level Expression Evaluation

Escaped Characters

Deprecated Expressions

Introduction¶

Generator expressions are evaluated during build system generation to produce
information specific to each build configuration.  They have the form
$<...>.  For example:

target_include_directories(tgt PRIVATE /opt/include/$<CXX_COMPILER_ID>)

This would expand to /opt/include/GNU, /opt/include/Clang, etc.
depending on the C++ compiler used.

Generator expressions are allowed in the context of many target properties,
such as LINK_LIBRARIES, INCLUDE_DIRECTORIES,
COMPILE_DEFINITIONS and others.  They may also be used when using
commands to populate those properties, such as target_link_libraries(),
target_include_directories(), target_compile_definitions()
and others.  They enable conditional linking, conditional definitions used when
compiling, conditional include directories, and more.  The conditions may be
based on the build configuration, target properties, platform information,
or any other queryable information.

Generator expressions can be nested:

target_compile_definitions(tgt PRIVATE
  $<$<VERSION_LESS:$<CXX_COMPILER_VERSION>,4.2.0>:OLD_COMPILER>
)

The above would expand to OLD_COMPILER if the
CMAKE_CXX_COMPILER_VERSION is less
than 4.2.0.

Whitespace And Quoting¶

Generator expressions are typically parsed after command arguments.
If a generator expression contains spaces, new lines, semicolons or
other characters that may be interpreted as command argument separators,
the whole expression should be surrounded by quotes when passed to a
command.  Failure to do so may result in the expression being split and
it may no longer be recognized as a generator expression.

When using add_custom_command() or add_custom_target(),
use the VERBATIM and COMMAND_EXPAND_LISTS options to obtain robust
argument splitting and quoting.

# WRONG: Embedded space will be treated as an argument separator.
# This ends up not being seen as a generator expression at all.
add_custom_target(run_some_tool
  COMMAND some_tool -I$<JOIN:$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>, -I>
  VERBATIM
)

# Better, but still not robust. Quotes prevent the space from splitting the
# expression. However, the tool will receive the expanded value as a single
# argument.
add_custom_target(run_some_tool
  COMMAND some_tool "-I$<JOIN:$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>, -I>"
  VERBATIM
)

# Nearly correct. Using a semicolon to separate arguments and adding the
# COMMAND_EXPAND_LISTS option means that paths with spaces will be handled
# correctly. Quoting the whole expression ensures it is seen as a generator
# expression. But if the target property is empty, we will get a bare -I
# with nothing after it.
add_custom_target(run_some_tool
  COMMAND some_tool "-I$<JOIN:$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>,;-I>"
  COMMAND_EXPAND_LISTS
  VERBATIM
)

Using variables to build up a more complex generator expression is also a
good way to reduce errors and improve readability.  The above example can be
improved further like so:

# The $<BOOL:...> check prevents adding anything if the property is empty,
# assuming the property value cannot be one of CMake's false constants.
set(prop "$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>")
add_custom_target(run_some_tool
  COMMAND some_tool "$<$<BOOL:${prop}>:-I$<JOIN:${prop},;-I>>"
  COMMAND_EXPAND_LISTS
  VERBATIM
)

Finally, the above example can be expressed in a more simple and robust way
using an alternate generator expression:

add_custom_target(run_some_tool
  COMMAND some_tool "$<LIST:TRANSFORM,$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>,PREPEND,-I>"
  COMMAND_EXPAND_LISTS
  VERBATIM
)

A common mistake is to try to split a generator expression across multiple
lines with indenting:

# WRONG: New lines and spaces all treated as argument separators, so the
# generator expression is split and not recognized correctly.
target_compile_definitions(tgt PRIVATE
  $<$<AND:
      $<CXX_COMPILER_ID:GNU>,
      $<VERSION_GREATER_EQUAL:$<CXX_COMPILER_VERSION>,5>
    >:HAVE_5_OR_LATER>
)

Again, use helper variables with well-chosen names to build up a readable
expression instead:

set(is_gnu "$<CXX_COMPILER_ID:GNU>")
set(v5_or_later "$<VERSION_GREATER_EQUAL:$<CXX_COMPILER_VERSION>,5>")
set(meet_requirements "$<AND:${is_gnu},${v5_or_later}>")
target_compile_definitions(tgt PRIVATE
  "$<${meet_requirements}:HAVE_5_OR_LATER>"
)

Debugging¶

Since generator expressions are evaluated during generation of the buildsystem,
and not during processing of CMakeLists.txt files, it is not possible to
inspect their result with the message() command.  One possible way
to generate debug messages is to add a custom target:

add_custom_target(genexdebug COMMAND ${CMAKE_COMMAND} -E echo "$<...>")

After running cmake, you can then build the genexdebug target to print
the result of the $<...> expression (i.e. run the command
cmake --build ... --target genexdebug).

Another way is to write debug messages to a file with file(GENERATE):

file(GENERATE OUTPUT filename CONTENT "$<...>")

Generator Expression Reference¶

Note

This reference deviates from most of the CMake documentation in that it
omits angular brackets <...> around placeholders like condition,
string, target, etc.  This is to prevent an opportunity for those
placeholders to be misinterpreted as generator expressions.

Conditional Expressions¶

A fundamental category of generator expressions relates to conditional logic.
Two forms of conditional generator expressions are supported:

$<condition:true_string>¶

Evaluates to true_string if condition is 1, or an empty string
if condition evaluates to 0.  Any other value for condition
results in an error.

$<IF:condition,true_string,false_string>¶

New in version 3.8.

Evaluates to true_string if condition is 1, or false_string
if condition is 0.  Any other value for condition results in an
error.

New in version 3.28: This generator expression short-circuits such that generator expressions in
false_string will not evaluate when condition is 1, and generator
expressions in true_string will not evaluate when condition is 0.

Typically, the condition is itself a generator expression.  For instance,
the following expression expands to DEBUG_MODE when the Debug
configuration is used, and the empty string for all other configurations:

$<$<CONFIG:Debug>:DEBUG_MODE>

Boolean-like condition values other than 1 or 0 can be handled
by wrapping them with the $<BOOL:...> generator expression:

$<BOOL:string>¶

Converts string to 0 or 1. Evaluates to 0 if any of the
following is true:

string is empty,

string is a case-insensitive equal of
0, FALSE, OFF, N, NO, IGNORE, or NOTFOUND, or

string ends in the suffix -NOTFOUND (case-sensitive).

Otherwise evaluates to 1.

The $<BOOL:...> generator expression is often used when a condition
is provided by a CMake variable:

$<$<BOOL:${HAVE_SOME_FEATURE}>:-DENABLE_SOME_FEATURE>

Logical Operators¶

The common boolean logic operators are supported:

$<AND:conditions>¶

where conditions is a comma-separated list of boolean expressions,
all of which must evaluate to either 1 or 0.  The whole expression
evaluates to 1 if all conditions are 1.  If any condition is 0,
the whole expression evaluates to 0.

$<OR:conditions>¶

where conditions is a comma-separated list of boolean expressions.
all of which must evaluate to either 1 or 0.  The whole expression
evaluates to 1 if at least one of the conditions is 1.  If all
conditions evaluate to 0, the whole expression evaluates to 0.

$<NOT:condition>¶

condition must be 0 or 1.  The result of the expression is
0 if condition is 1, else 1.

New in version 3.28: Logical operators short-circuit such that generator expressions in the
arguments list will not be evaluated once a return value can be determined.

Primary Comparison Expressions¶

CMake supports a variety of generator expressions that compare things.
This section covers the primary and most widely used comparison types.
Other more specific comparison types are documented in their own separate
sections further below.

String Comparisons¶

$<STREQUAL:string1,string2>¶

1 if string1 and string2 are equal, else 0.
The comparison is case-sensitive.  For a case-insensitive comparison,
combine with a string transforming generator expression.  For example, the following
evaluates to 1 if ${foo} is any of BAR, Bar, bar, etc.

$<STREQUAL:$<UPPER_CASE:${foo}>,BAR>

$<EQUAL:value1,value2>¶

1 if value1 and value2 are numerically equal, else 0.

Version Comparisons¶

$<VERSION_LESS:v1,v2>¶

1 if v1 is a version less than v2, else 0.

$<VERSION_GREATER:v1,v2>¶

1 if v1 is a version greater than v2, else 0.

$<VERSION_EQUAL:v1,v2>¶

1 if v1 is the same version as v2, else 0.

$<VERSION_LESS_EQUAL:v1,v2>¶

New in version 3.7.

1 if v1 is a version less than or equal to v2, else 0.

$<VERSION_GREATER_EQUAL:v1,v2>¶

New in version 3.7.

1 if v1 is a version greater than or equal to v2, else 0.

String Transformations¶

$<LOWER_CASE:string>¶

Content of string converted to lower case.

$<UPPER_CASE:string>¶

Content of string converted to upper case.

$<MAKE_C_IDENTIFIER:...>¶

Content of ... converted to a C identifier.  The conversion follows the
same behavior as string(MAKE_C_IDENTIFIER).

List Expressions¶

Most of the expressions in this section are closely associated with the
list() command, providing the same capabilities, but in
the form of a generator expression.

In each of the following list-related generator expressions, the list
must not contain any commas if that generator expression expects something to
be provided after the list.  For example, the expression
$<LIST:FIND,list,value> requires a value after the list.
Since a comma is used to separate the list and the value, the list
cannot itself contain a comma.  This restriction does not apply to the
list() command, it is specific to the list-handling generator
expressions only.

List Comparisons¶

$<IN_LIST:string,list>¶

New in version 3.12.

1 if string is an item in the semicolon-separated list, else 0.
It uses case-sensitive comparisons.

List Queries¶

$<LIST:LENGTH,list>¶

New in version 3.27.

The number of items in the list.

$<LIST:GET,list,index,...>

New in version 3.27.

Expands to the list of items specified by indices from the list.

$<LIST:SUBLIST,list,begin,length>

New in version 3.27.

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, the remaining items of the list starting at
begin will be returned.

$<LIST:FIND,list,value>

New in version 3.27.

The index of the first item in list with the specified value,
or -1 if value is not in the list.

List Transformations¶

$<LIST:JOIN,list,glue>

New in version 3.27.

Converts list to a single string with the content of the glue string
inserted between each item.  This is conceptually the same operation as
$<JOIN:list,glue>, but the two have different behavior with regard
to empty items.  $<LIST:JOIN,list,glue> preserves all empty items,
whereas $<JOIN:list,glue> drops all empty items from the list.

$<LIST:APPEND,list,item,...>

New in version 3.27.

The list with each item appended.  Multiple items should be
separated by commas.

$<LIST:PREPEND,list,item,...>

New in version 3.27.

The list with each item inserted at the beginning.  If there are
multiple items, they should be separated by commas, and the order of the
prepended items will be preserved.

$<LIST:INSERT,list,index,item,...>

New in version 3.27.

The list with the item (or multiple items) inserted at the specified
index.  Multiple items should be separated by commas.

It is an error to specify an out-of-range index. Valid indexes are 0 to N,
where N is the length of the list, inclusive. An empty list has length 0.

$<LIST:POP_BACK,list>

New in version 3.27.

The list with the last item removed.

$<LIST:POP_FRONT,list>

New in version 3.27.

The list with the first item removed.

$<LIST:REMOVE_ITEM,list,value,...>

New in version 3.27.

The list with all instances of the given value (or values) removed.
If multiple values are given, they should be separated by commas.

$<LIST:REMOVE_AT,list,index,...>

New in version 3.27.

The list with the item at each given index removed.

$<LIST:REMOVE_DUPLICATES,list>

New in version 3.27.

The list with all duplicated items removed.  The relative order of
items is preserved, but if duplicates are encountered, only the first
instance is preserved.  The result is the same as
$<REMOVE_DUPLICATES:list>.

$<LIST:FILTER,list,INCLUDE|EXCLUDE,regex>

New in version 3.27.

A list of items from the list which match (INCLUDE) or do not match
(EXCLUDE) the regular expression regex.  The result is the same as
$<FILTER:list,INCLUDE|EXCLUDE,regex>.

$<LIST:TRANSFORM,list,ACTION[,SELECTOR]>

New in version 3.27.

The list transformed by applying an ACTION to all or, by
specifying a SELECTOR, to the selected list items.

Note

The TRANSFORM sub-command does not change the number of items in the
list. If a SELECTOR is specified, only some items will be changed,
the other ones will remain the same as before the transformation.

ACTION specifies the action to apply to the items of the list.
The actions have exactly the same semantics as for the
list(TRANSFORM) command.  ACTION must be one of the following:

APPEND, PREPEND

Append, prepend specified value to each item of the list.

$<LIST:TRANSFORM,list,(APPEND|PREPEND),value[,SELECTOR]>

TOLOWER, TOUPPER

Convert each item of the list to lower, upper characters.

$<LIST:TRANSFORM,list,(TOLOWER|TOUPPER)[,SELECTOR]>

STRIP

Remove leading and trailing spaces from each item of the list.

$<LIST:TRANSFORM,list,STRIP[,SELECTOR]>

REPLACE:

Match the regular expression as many times as possible and substitute
the replacement expression for the match for each item of the list.

$<LIST:TRANSFORM,list,REPLACE,regular_expression,replace_expression[,SELECTOR]>

SELECTOR determines which items 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 items matching the regular expression will be transformed.

$<LIST:TRANSFORM,list,ACTION,REGEX,regular_expression>

$<JOIN:list,glue>¶

Joins the list with the content of the glue string inserted between
each item.  This is conceptually the same operation as
$<LIST:JOIN,list,glue>, but the two have
different behavior with regard to empty items.
$<LIST:JOIN,list,glue> preserves all empty items,
whereas $<JOIN,list,glue> drops all empty items from the list.

$<REMOVE_DUPLICATES:list>¶

New in version 3.15.

Removes duplicated items in the given list. The relative order of items
is preserved, and if duplicates are encountered, only the first instance is
retained.  The result is the same as
$<LIST:REMOVE_DUPLICATES,list>.

$<FILTER:list,INCLUDE|EXCLUDE,regex>¶

New in version 3.15.

Includes or removes items from list that match the regular expression
regex.  The result is the same as
$<LIST:FILTER,list,INCLUDE|EXCLUDE,regex>.

List Ordering¶

$<LIST:REVERSE,list>

New in version 3.27.

The list with the items in reverse order.

$<LIST:SORT,list[,(COMPARE:option|CASE:option|ORDER:option)]...>

New in version 3.27.

The list sorted according to the specified options.

Use one of the COMPARE options to select the comparison method
for sorting:

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 file paths by their basenames.

NATURAL

Sorts a list of strings using natural order (see the man page for
strverscmp(3)), 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, whereas it will be sorted as
1.1 10.0 2.0 2.1 3.1 8.0 with the STRING comparison.

Use one of the CASE options to select a case-sensitive or
case-insensitive sort mode:

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 in a case-insensitive manner.  The order of
items which differ only by upper/lowercase is not specified.

To control the sort order, one of the ORDER options can be given:

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.

Options can be specified in any order, but it is an error to specify the
same option multiple times.

$<LIST:SORT,list,CASE:SENSITIVE,COMPARE:STRING,ORDER:DESCENDING>

Path Expressions¶

Most of the expressions in this section are closely associated with the
cmake_path() command, providing the same capabilities, but in
the form of a generator expression.

For all generator expressions in this section, paths are expected to be in
cmake-style format. The $<PATH:CMAKE_PATH>
generator expression can be used to convert a native path to a cmake-style
one.

Path Comparisons¶

$<PATH_EQUAL:path1,path2>¶

New in version 3.24.

Compares the lexical representations of two paths. No normalization is
performed on either path. Returns 1 if the paths are equal, 0
otherwise.

See cmake_path(COMPARE) for more details.

Path Queries¶

These expressions provide the generation-time capabilities equivalent to the
Query options of the cmake_path() command.
All paths are expected to be in cmake-style format.

$<PATH:HAS_*,path>¶

New in version 3.24.

The following operations return 1 if the particular path component is
present, 0 otherwise. See Path Structure And Terminology for the
meaning of each path component.

$<PATH:HAS_ROOT_NAME,path>
$<PATH:HAS_ROOT_DIRECTORY,path>
$<PATH:HAS_ROOT_PATH,path>
$<PATH:HAS_FILENAME,path>
$<PATH:HAS_EXTENSION,path>
$<PATH:HAS_STEM,path>
$<PATH:HAS_RELATIVE_PART,path>
$<PATH:HAS_PARENT_PATH,path>

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.

$<PATH:IS_ABSOLUTE,path>

New in version 3.24.

Returns 1 if the path is absolute, 0 otherwise.

$<PATH:IS_RELATIVE,path>

New in version 3.24.

This will return the opposite of IS_ABSOLUTE.

$<PATH:IS_PREFIX[,NORMALIZE],path,input>

New in version 3.24.

Returns 1 if path is the prefix of input, 0 otherwise.

When the NORMALIZE option is specified, path and input are
normalized before the check.

Path Decomposition¶

These expressions provide the generation-time capabilities equivalent to the
Decomposition options of the cmake_path()
command.  All paths are expected to be in cmake-style format.

$<PATH:GET_*,...>

New in version 3.24.

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

Changed in version 3.27: All operations now accept a list of paths as argument. When a list of paths
is specified, the operation will be applied to each path.

$<PATH:GET_ROOT_NAME,path...>
$<PATH:GET_ROOT_DIRECTORY,path...>
$<PATH:GET_ROOT_PATH,path...>
$<PATH:GET_FILENAME,path...>
$<PATH:GET_EXTENSION[,LAST_ONLY],path...>
$<PATH:GET_STEM[,LAST_ONLY],path...>
$<PATH:GET_RELATIVE_PART,path...>
$<PATH:GET_PARENT_PATH,path...>

If a requested component is not present in the path, an empty string is
returned.

Path Transformations¶

These expressions provide the generation-time capabilities equivalent to the
Modification and Generation
options of the cmake_path() command.  All paths are expected to be
in cmake-style format.

Changed in version 3.27: All operations now accept a list of paths as argument. When a list of paths
is specified, the operation will be applied to each path.

$<PATH:CMAKE_PATH[,NORMALIZE],path...>

New in version 3.24.

Returns path. If path is a native path, it is converted into a
cmake-style path with forward-slashes (/). On Windows, the long filename
marker is taken into account.

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

$<PATH:APPEND,path...,input,...>

New in version 3.24.

Returns all the input arguments appended to path using / as the
directory-separator. Depending on the input, the value of path
may be discarded.

See cmake_path(APPEND) for more details.

$<PATH:REMOVE_FILENAME,path...>

New in version 3.24.

Returns path with filename component (as returned by
$<PATH:GET_FILENAME>) removed. After removal, any trailing
directory-separator is left alone, if present.

See cmake_path(REMOVE_FILENAME) for more details.

$<PATH:REPLACE_FILENAME,path...,input>

New in version 3.24.

Returns path with the filename component replaced by input. If
path has no filename component (i.e. $<PATH:HAS_FILENAME> returns
0), path is unchanged.

See cmake_path(REPLACE_FILENAME) for more details.

$<PATH:REMOVE_EXTENSION[,LAST_ONLY],path...>

New in version 3.24.

Returns path with the extension removed, if any.

See cmake_path(REMOVE_EXTENSION) for more details.

$<PATH:REPLACE_EXTENSION[,LAST_ONLY],path...,input>

New in version 3.24.

Returns path with the extension replaced by
input, if any.

See cmake_path(REPLACE_EXTENSION) for more details.

$<PATH:NORMAL_PATH,path...>

New in version 3.24.

Returns path normalized according to the steps described in
Normalization.

$<PATH:RELATIVE_PATH,path...,base_directory>

New in version 3.24.

Returns path, modified to make it relative to the base_directory
argument.

See cmake_path(RELATIVE_PATH) for more
details.

$<PATH:ABSOLUTE_PATH[,NORMALIZE],path...,base_directory>

New in version 3.24.

Returns path as absolute. If path is a relative path
($<PATH:IS_RELATIVE> returns 1), it is evaluated relative to the
given base directory specified by base_directory argument.

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

See cmake_path(ABSOLUTE_PATH) for more details.

Shell Paths¶

$<SHELL_PATH:...>¶

New in version 3.4.

Content of ... converted to shell path style. For example, slashes are
converted to backslashes in Windows shells and drive letters are converted
to posix paths in MSYS shells. The ... must be an absolute path.

New in version 3.14: The ... may be a semicolon-separated list
of paths, in which case each path is converted individually and a result
list is generated using the shell path separator (: on POSIX and
; on Windows).  Be sure to enclose the argument containing this genex
in double quotes in CMake source code so that ; does not split arguments.

Configuration Expressions¶

$<CONFIG>¶

Configuration name. Use this instead of the deprecated CONFIGURATION
generator expression.

$<CONFIG:cfgs>

1 if config is any one of the entries in comma-separated list
cfgs, else 0. This is a case-insensitive comparison. The mapping in
MAP_IMPORTED_CONFIG_<CONFIG> is also considered by this
expression when it is evaluated on a property of an IMPORTED
target.

Changed in version 3.19: Multiple configurations can be specified for cfgs.
CMake 3.18 and earlier only accepted a single configuration.

$<OUTPUT_CONFIG:...>¶

New in version 3.20.

Only valid in add_custom_command() and add_custom_target()
as the outer-most generator expression in an argument.
With the Ninja Multi-Config generator, generator expressions
in ... are evaluated using the custom command's "output config".
With other generators, the content of ... is evaluated normally.

$<COMMAND_CONFIG:...>¶

New in version 3.20.

Only valid in add_custom_command() and add_custom_target()
as the outer-most generator expression in an argument.
With the Ninja Multi-Config generator, generator expressions
in ... are evaluated using the custom command's "command config".
With other generators, the content of ... is evaluated normally.

Toolchain And Language Expressions¶

Platform¶

$<PLATFORM_ID>¶

The current system's CMake platform id.
See also the CMAKE_SYSTEM_NAME variable.

$<PLATFORM_ID:platform_ids>

1 if CMake's platform id matches any one of the entries in
comma-separated list platform_ids, otherwise 0.
See also the CMAKE_SYSTEM_NAME variable.

Compiler Version¶

See also the CMAKE_<LANG>_COMPILER_VERSION variable, which is
closely related to the expressions in this sub-section.

$<C_COMPILER_VERSION>¶

The version of the C compiler used.

$<C_COMPILER_VERSION:version>

1 if the version of the C compiler matches version, otherwise 0.

$<CXX_COMPILER_VERSION>¶

The version of the CXX compiler used.

$<CXX_COMPILER_VERSION:version>

1 if the version of the CXX compiler matches version, otherwise 0.

$<CUDA_COMPILER_VERSION>¶

New in version 3.15.

The version of the CUDA compiler used.

$<CUDA_COMPILER_VERSION:version>

New in version 3.15.

1 if the version of the CXX compiler matches version, otherwise 0.

$<OBJC_COMPILER_VERSION>¶

New in version 3.16.

The version of the OBJC compiler used.

$<OBJC_COMPILER_VERSION:version>

New in version 3.16.

1 if the version of the OBJC compiler matches version, otherwise 0.

$<OBJCXX_COMPILER_VERSION>¶

New in version 3.16.

The version of the OBJCXX compiler used.

$<OBJCXX_COMPILER_VERSION:version>

New in version 3.16.

1 if the version of the OBJCXX compiler matches version, otherwise 0.

$<Fortran_COMPILER_VERSION>¶

The version of the Fortran compiler used.

$<Fortran_COMPILER_VERSION:version>

1 if the version of the Fortran compiler matches version, otherwise 0.

$<HIP_COMPILER_VERSION>¶

New in version 3.21.

The version of the HIP compiler used.

$<HIP_COMPILER_VERSION:version>

New in version 3.21.

1 if the version of the HIP compiler matches version, otherwise 0.

$<ISPC_COMPILER_VERSION>¶

New in version 3.19.

The version of the ISPC compiler used.

$<ISPC_COMPILER_VERSION:version>

New in version 3.19.

1 if the version of the ISPC compiler matches version, otherwise 0.

Compiler Language And ID¶

See also the CMAKE_<LANG>_COMPILER_ID variable, which is closely
related to most of the expressions in this sub-section.

$<C_COMPILER_ID>¶

CMake's compiler id of the C compiler used.

$<C_COMPILER_ID:compiler_ids>

where compiler_ids is a comma-separated list.
1 if CMake's compiler id of the C compiler matches any one
of the entries in compiler_ids, otherwise 0.

Changed in version 3.15: Multiple compiler_ids can be specified.
CMake 3.14 and earlier only accepted a single compiler ID.

$<CXX_COMPILER_ID>¶

CMake's compiler id of the CXX compiler used.

$<CXX_COMPILER_ID:compiler_ids>

where compiler_ids is a comma-separated list.
1 if CMake's compiler id of the CXX compiler matches any one
of the entries in compiler_ids, otherwise 0.

Changed in version 3.15: Multiple compiler_ids can be specified.
CMake 3.14 and earlier only accepted a single compiler ID.

$<CUDA_COMPILER_ID>¶

New in version 3.15.

CMake's compiler id of the CUDA compiler used.

$<CUDA_COMPILER_ID:compiler_ids>

New in version 3.15.

where compiler_ids is a comma-separated list.
1 if CMake's compiler id of the CUDA compiler matches any one
of the entries in compiler_ids, otherwise 0.

$<OBJC_COMPILER_ID>¶

New in version 3.16.

CMake's compiler id of the OBJC compiler used.

$<OBJC_COMPILER_ID:compiler_ids>

New in version 3.16.

where compiler_ids is a comma-separated list.
1 if CMake's compiler id of the Objective-C compiler matches any one
of the entries in compiler_ids, otherwise 0.

$<OBJCXX_COMPILER_ID>¶

New in version 3.16.

CMake's compiler id of the OBJCXX compiler used.

$<OBJCXX_COMPILER_ID:compiler_ids>

New in version 3.16.

where compiler_ids is a comma-separated list.
1 if CMake's compiler id of the Objective-C++ compiler matches any one
of the entries in compiler_ids, otherwise 0.

$<Fortran_COMPILER_ID>¶

CMake's compiler id of the Fortran compiler used.

$<Fortran_COMPILER_ID:compiler_ids>

where compiler_ids is a comma-separated list.
1 if CMake's compiler id of the Fortran compiler matches any one
of the entries in compiler_ids, otherwise 0.

Changed in version 3.15: Multiple compiler_ids can be specified.
CMake 3.14 and earlier only accepted a single compiler ID.

$<HIP_COMPILER_ID>¶

New in version 3.21.

CMake's compiler id of the HIP compiler used.

$<HIP_COMPILER_ID:compiler_ids>

New in version 3.21.

where compiler_ids is a comma-separated list.
1 if CMake's compiler id of the HIP compiler matches any one
of the entries in compiler_ids, otherwise 0.

$<ISPC_COMPILER_ID>¶

New in version 3.19.

CMake's compiler id of the ISPC compiler used.

$<ISPC_COMPILER_ID:compiler_ids>

New in version 3.19.

where compiler_ids is a comma-separated list.
1 if CMake's compiler id of the ISPC compiler matches any one
of the entries in compiler_ids, otherwise 0.

$<COMPILE_LANGUAGE>¶

New in version 3.3.

The compile language of source files when evaluating compile options.
See the related boolean expression
$<COMPILE_LANGUAGE:language>
for notes about the portability of this generator expression.

$<COMPILE_LANGUAGE:languages>

New in version 3.3.

Changed in version 3.15: Multiple languages can be specified for languages.
CMake 3.14 and earlier only accepted a single language.

1 when the language used for compilation unit matches any of the
comma-separated entries in languages, otherwise 0. This expression
may be used to specify compile options, compile definitions, and include
directories for source files of a particular language in a target. For
example:

add_executable(myapp main.cpp foo.c bar.cpp zot.cu)
target_compile_options(myapp
  PRIVATE $<$<COMPILE_LANGUAGE:CXX>:-fno-exceptions>
)
target_compile_definitions(myapp
  PRIVATE $<$<COMPILE_LANGUAGE:CXX>:COMPILING_CXX>
          $<$<COMPILE_LANGUAGE:CUDA>:COMPILING_CUDA>
)
target_include_directories(myapp
  PRIVATE $<$<COMPILE_LANGUAGE:CXX,CUDA>:/opt/foo/headers>
)

This specifies the use of the -fno-exceptions compile option,
COMPILING_CXX compile definition, and cxx_headers include
directory for C++ only (compiler id checks elided).  It also specifies
a COMPILING_CUDA compile definition for CUDA.

Note that with Visual Studio Generators and Xcode there
is no way to represent target-wide compile definitions or include directories
separately for C and CXX languages.
Also, with Visual Studio Generators there is no way to represent
target-wide flags separately for C and CXX languages.  Under these
generators, expressions for both C and C++ sources will be evaluated
using CXX if there are any C++ sources and otherwise using C.
A workaround is to create separate libraries for each source file language
instead:

add_library(myapp_c foo.c)
add_library(myapp_cxx bar.cpp)
target_compile_options(myapp_cxx PUBLIC -fno-exceptions)
add_executable(myapp main.cpp)
target_link_libraries(myapp myapp_c myapp_cxx)

$<COMPILE_LANG_AND_ID:language,compiler_ids>¶

New in version 3.15.

1 when the language used for compilation unit matches language and
CMake's compiler id of the language compiler matches any one of the
comma-separated entries in compiler_ids, otherwise 0. This expression
is a short form for the combination of $<COMPILE_LANGUAGE:language> and
$<LANG_COMPILER_ID:compiler_ids>. This expression may be used to specify
compile options, compile definitions, and include directories for source
files of a particular language and compiler combination in a target.
For example:

add_executable(myapp main.cpp foo.c bar.cpp zot.cu)
target_compile_definitions(myapp
  PRIVATE $<$<COMPILE_LANG_AND_ID:CXX,AppleClang,Clang>:COMPILING_CXX_WITH_CLANG>
          $<$<COMPILE_LANG_AND_ID:CXX,Intel>:COMPILING_CXX_WITH_INTEL>
          $<$<COMPILE_LANG_AND_ID:C,Clang>:COMPILING_C_WITH_CLANG>
)

This specifies the use of different compile definitions based on both
the compiler id and compilation language. This example will have a
COMPILING_CXX_WITH_CLANG compile definition when Clang is the CXX
compiler, and COMPILING_CXX_WITH_INTEL when Intel is the CXX compiler.
Likewise, when the C compiler is Clang, it will only see the
COMPILING_C_WITH_CLANG definition.

Without the COMPILE_LANG_AND_ID generator expression, the same logic
would be expressed as:

target_compile_definitions(myapp
  PRIVATE $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:AppleClang,Clang>>:COMPILING_CXX_WITH_CLANG>
          $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:Intel>>:COMPILING_CXX_WITH_INTEL>
          $<$<AND:$<COMPILE_LANGUAGE:C>,$<C_COMPILER_ID:Clang>>:COMPILING_C_WITH_CLANG>
)

Compile Features¶

$<COMPILE_FEATURES:features>¶

New in version 3.1.

where features is a comma-separated list.
Evaluates to 1 if all of the features are available for the 'head'
target, and 0 otherwise. If this expression is used while evaluating
the link implementation of a target and if any dependency transitively
increases the required C_STANDARD or CXX_STANDARD
for the 'head' target, an error is reported.  See the
cmake-compile-features(7) manual for information on
compile features and a list of supported compilers.

Compile Context¶

$<COMPILE_ONLY:...>¶

New in version 3.27.

Content of ..., when collecting Transitive Usage Requirements,
otherwise it is the empty string.  This is intended for use in an
INTERFACE_LINK_LIBRARIES and LINK_LIBRARIES target
properties, typically populated via the target_link_libraries() command.
Provides compilation usage requirements without any linking requirements.

Use cases include header-only usage where all usages are known to not have
linking requirements (e.g., all-inline or C++ template libraries).

Note that for proper evaluation of this expression requires policy CMP0099
to be set to NEW.

Linker Language And ID¶

$<LINK_LANGUAGE>¶

New in version 3.18.

The link language of the target when evaluating link options.
See the related boolean expression $<LINK_LANGUAGE:languages>
for notes about the portability of this generator expression.

Note

This generator expression is not supported by the link libraries
properties to avoid side-effects due to the double evaluation of
these properties.

$<LINK_LANGUAGE:languages>

New in version 3.18.

1 when the language used for link step matches any of the comma-separated
entries in languages, otherwise 0.  This expression may be used to
specify link libraries, link options, link directories and link dependencies
of a particular language in a target. For example:

add_library(api_C ...)
add_library(api_CXX ...)
add_library(api INTERFACE)
target_link_options(api   INTERFACE $<$<LINK_LANGUAGE:C>:-opt_c>
                                    $<$<LINK_LANGUAGE:CXX>:-opt_cxx>)
target_link_libraries(api INTERFACE $<$<LINK_LANGUAGE:C>:api_C>
                                    $<$<LINK_LANGUAGE:CXX>:api_CXX>)

add_executable(myapp1 main.c)
target_link_options(myapp1 PRIVATE api)

add_executable(myapp2 main.cpp)
target_link_options(myapp2 PRIVATE api)

This specifies to use the api target for linking targets myapp1 and
myapp2. In practice, myapp1 will link with target api_C and
option -opt_c because it will use C as link language. And myapp2
will link with api_CXX and option -opt_cxx because CXX will be
the link language.

Note

To determine the link language of a target, it is required to collect,
transitively, all the targets which will be linked to it. So, for link
libraries properties, a double evaluation will be done. During the first
evaluation, $<LINK_LANGUAGE:..> expressions will always return 0.
The link language computed after this first pass will be used to do the
second pass. To avoid inconsistency, it is required that the second pass
do not change the link language. Moreover, to avoid unexpected
side-effects, it is required to specify complete entities as part of the
$<LINK_LANGUAGE:..> expression. For example:

add_library(lib STATIC file.cxx)
add_library(libother STATIC file.c)

# bad usage
add_executable(myapp1 main.c)
target_link_libraries(myapp1 PRIVATE lib$<$<LINK_LANGUAGE:C>:other>)

# correct usage
add_executable(myapp2 main.c)
target_link_libraries(myapp2 PRIVATE $<$<LINK_LANGUAGE:C>:libother>)

In this example, for myapp1, the first pass will, unexpectedly,
determine that the link language is CXX because the evaluation of the
generator expression will be an empty string so myapp1 will depends on
target lib which is C++. On the contrary, for myapp2, the first
evaluation will give C as link language, so the second pass will
correctly add target libother as link dependency.

$<LINK_LANG_AND_ID:language,compiler_ids>¶

New in version 3.18.

1 when the language used for link step matches language and the
CMake's compiler id of the language linker matches any one of the comma-separated
entries in compiler_ids, otherwise 0. This expression is a short form
for the combination of $<LINK_LANGUAGE:language> and
$<LANG_COMPILER_ID:compiler_ids>. This expression may be used to specify
link libraries, link options, link directories and link dependencies of a
particular language and linker combination in a target. For example:

add_library(libC_Clang ...)
add_library(libCXX_Clang ...)
add_library(libC_Intel ...)
add_library(libCXX_Intel ...)

add_executable(myapp main.c)
if (CXX_CONFIG)
  target_sources(myapp PRIVATE file.cxx)
endif()
target_link_libraries(myapp
  PRIVATE $<$<LINK_LANG_AND_ID:CXX,Clang,AppleClang>:libCXX_Clang>
          $<$<LINK_LANG_AND_ID:C,Clang,AppleClang>:libC_Clang>
          $<$<LINK_LANG_AND_ID:CXX,Intel>:libCXX_Intel>
          $<$<LINK_LANG_AND_ID:C,Intel>:libC_Intel>)

This specifies the use of different link libraries based on both the
compiler id and link language. This example will have target libCXX_Clang
as link dependency when Clang or AppleClang is the CXX
linker, and libCXX_Intel when Intel is the CXX linker.
Likewise when the C linker is Clang or AppleClang, target
libC_Clang will be added as link dependency and libC_Intel when
Intel is the C linker.

See the note related to
$<LINK_LANGUAGE:language> for constraints about the usage of this
generator expression.

Link Features¶

$<LINK_LIBRARY:feature,library-list>¶

New in version 3.24.

Specify a set of libraries to link to a target, along with a feature
which provides details about how they should be linked.  For example:

add_library(lib1 STATIC ...)
add_library(lib2 ...)
target_link_libraries(lib2 PRIVATE "$<LINK_LIBRARY:WHOLE_ARCHIVE,lib1>")

This specifies that lib2 should link to lib1 and use the
WHOLE_ARCHIVE feature when doing so.

Feature names are case-sensitive and may only contain letters, numbers and
underscores.  Feature names defined in all uppercase are reserved for CMake's
own built-in features.  The pre-defined built-in library features are:

DEFAULT

This feature corresponds to standard linking, essentially equivalent to
using no feature at all.  It is typically only used with the
LINK_LIBRARY_OVERRIDE and
LINK_LIBRARY_OVERRIDE_<LIBRARY> target properties.

WHOLE_ARCHIVE

Force inclusion of all members of a static library.  This feature is only
supported for the following platforms, with limitations as noted:

Linux.

All BSD variants.

SunOS.

All Apple variants.  The library must be specified as a CMake target name,
a library file name (such as libfoo.a), or a library file path (such as
/path/to/libfoo.a).  Due to a limitation of the Apple linker, it
cannot be specified as a plain library name like foo, where foo
is not a CMake target.

Windows.  When using a MSVC or MSVC-like toolchain, the MSVC version must
be greater than 1900.

Cygwin.

MSYS.

FRAMEWORK

This option tells the linker to search for the specified framework using
the -framework linker option.  It can only be used on Apple platforms,
and only with a linker that understands the option used (i.e. the linker
provided with Xcode, or one compatible with it).

The framework can be specified as a CMake framework target, a bare framework
name, or a file path.  If a target is given, that target must have the
FRAMEWORK target property set to true.  For a file path, if it
contains a directory part, that directory will be added as a framework
search path.

add_library(lib SHARED ...)
target_link_libraries(lib PRIVATE "$<LINK_LIBRARY:FRAMEWORK,/path/to/my_framework>")

# The constructed linker command line will contain:
#   -F/path/to -framework my_framework

File paths must conform to one of the following patterns (* is a
wildcard, and optional parts are shown as [...]):

[/path/to/]FwName[.framework]

[/path/to/]FwName.framework/FwName[suffix]

[/path/to/]FwName.framework/Versions/*/FwName[suffix]

Note that CMake recognizes and automatically handles framework targets,
even without using the $<LINK_LIBRARY:FRAMEWORK,...> expression.
The generator expression can still be used with a CMake target if the
project wants to be explicit about it, but it is not required to do so.
The linker command line may have some differences between using the
generator expression or not, but the final result should be the same.
On the other hand, if a file path is given, CMake will recognize some paths
automatically, but not all cases.  The project may want to use
$<LINK_LIBRARY:FRAMEWORK,...> for file paths so that the expected
behavior is clear.

New in version 3.25: The FRAMEWORK_MULTI_CONFIG_POSTFIX_<CONFIG> target property as
well as the suffix of the framework library name are now supported by
the FRAMEWORK features.

NEEDED_FRAMEWORK

This is similar to the FRAMEWORK feature, except it forces the linker
to link with the framework even if no symbols are used from it.  It uses
the -needed_framework option and has the same linker constraints as
FRAMEWORK.

REEXPORT_FRAMEWORK

This is similar to the FRAMEWORK feature, except it tells the linker
that the framework should be available to clients linking to the library
being created.  It uses the -reexport_framework option and has the
same linker constraints as FRAMEWORK.

WEAK_FRAMEWORK

This is similar to the FRAMEWORK feature, except it forces the linker
to mark the framework and all references to it as weak imports.  It uses
the -weak_framework option and has the same linker constraints as
FRAMEWORK.

NEEDED_LIBRARY

This is similar to the NEEDED_FRAMEWORK feature, except it is for use
with non-framework targets or libraries (Apple platforms only).
It uses the -needed_library or -needed-l option as appropriate,
and has the same linker constraints as NEEDED_FRAMEWORK.

REEXPORT_LIBRARY

This is similar to the REEXPORT_FRAMEWORK feature,  except it is for use
with non-framework targets or libraries (Apple platforms only).
It uses the -reexport_library or -reexport-l option as appropriate,
and has the same linker constraints as REEXPORT_FRAMEWORK.

WEAK_LIBRARY

This is similar to the WEAK_FRAMEWORK feature, except it is for use
with non-framework targets or libraries (Apple platforms only).
It uses the -weak_library or -weak-l option as appropriate,
and has the same linker constraints as WEAK_FRAMEWORK.

Built-in and custom library features are defined in terms of the following
variables:

CMAKE_<LANG>_LINK_LIBRARY_USING_<FEATURE>_SUPPORTED

CMAKE_<LANG>_LINK_LIBRARY_USING_<FEATURE>

CMAKE_LINK_LIBRARY_USING_<FEATURE>_SUPPORTED

CMAKE_LINK_LIBRARY_USING_<FEATURE>

The value used for each of these variables is the value as set at the end of
the directory scope in which the target was created.  The usage is as follows:

If the language-specific
CMAKE_<LANG>_LINK_LIBRARY_USING_<FEATURE>_SUPPORTED variable
is true, the feature must be defined by the corresponding
CMAKE_<LANG>_LINK_LIBRARY_USING_<FEATURE> variable.

If no language-specific feature is supported, then the
CMAKE_LINK_LIBRARY_USING_<FEATURE>_SUPPORTED variable must be
true and the feature must be defined by the corresponding
CMAKE_LINK_LIBRARY_USING_<FEATURE> variable.

The following limitations should be noted:

The library-list can specify CMake targets or libraries.
Any CMake target of type OBJECT
or INTERFACE will ignore the feature aspect
of the expression and instead be linked in the standard way.

The $<LINK_LIBRARY:...> generator expression can only be used to
specify link libraries.  In practice, this means it can appear in the
LINK_LIBRARIES, INTERFACE_LINK_LIBRARIES, and
INTERFACE_LINK_LIBRARIES_DIRECT  target properties, and be
specified in target_link_libraries() and link_libraries()
commands.

If a $<LINK_LIBRARY:...> generator expression appears in the
INTERFACE_LINK_LIBRARIES property of a target, it will be
included in the imported target generated by a install(EXPORT)
command.  It is the responsibility of the environment consuming this
import to define the link feature used by this expression.

Each target or library involved in the link step must have at most only
one kind of library feature.  The absence of a feature is also incompatible
with all other features.  For example:

add_library(lib1 ...)
add_library(lib2 ...)
add_library(lib3 ...)

# lib1 will be associated with feature1
target_link_libraries(lib2 PUBLIC "$<LINK_LIBRARY:feature1,lib1>")

# lib1 is being linked with no feature here. This conflicts with the
# use of feature1 in the line above and would result in an error.
target_link_libraries(lib3 PRIVATE lib1 lib2)

Where it isn't possible to use the same feature throughout a build for a
given target or library, the LINK_LIBRARY_OVERRIDE and
LINK_LIBRARY_OVERRIDE_<LIBRARY> target properties can be
used to resolve such incompatibilities.

The $<LINK_LIBRARY:...> generator expression does not guarantee
that the list of specified targets and libraries will be kept grouped
together.  To manage constructs like --start-group and --end-group,
as supported by the GNU ld linker, use the LINK_GROUP
generator expression instead.

$<LINK_GROUP:feature,library-list>¶

New in version 3.24.

Specify a group of libraries to link to a target, along with a feature
which defines how that group should be linked.  For example:

add_library(lib1 STATIC ...)
add_library(lib2 ...)
target_link_libraries(lib2 PRIVATE "$<LINK_GROUP:RESCAN,lib1,external>")

This specifies that lib2 should link to lib1 and external, and
that both of those two libraries should be included on the linker command
line according to the definition of the RESCAN feature.

Feature names are case-sensitive and may only contain letters, numbers and
underscores.  Feature names defined in all uppercase are reserved for CMake's
own built-in features.  Currently, there is only one pre-defined built-in
group feature:

RESCAN

Some linkers are single-pass only.  For such linkers, circular references
between libraries typically result in unresolved symbols.  This feature
instructs the linker to search the specified static libraries repeatedly
until no new undefined references are created.

Normally, a static library is searched only once in the order that it is
specified on the command line.  If a symbol in that library is needed to
resolve an undefined symbol referred to by an object in a library that
appears later on the command line, the linker would not be able to resolve
that reference.  By grouping the static libraries with the RESCAN
feature, they will all be searched repeatedly until all possible references
are resolved.  This will use linker options like --start-group and
--end-group, or on SunOS, -z rescan-start and -z rescan-end.

Using this feature has a significant performance cost. It is best to use it
only when there are unavoidable circular references between two or more
static libraries.

This feature is available when using toolchains that target Linux, BSD, and
SunOS.  It can also be used when targeting Windows platforms if the GNU
toolchain is used.

Built-in and custom group features are defined in terms of the following
variables:

CMAKE_<LANG>_LINK_GROUP_USING_<FEATURE>_SUPPORTED

CMAKE_<LANG>_LINK_GROUP_USING_<FEATURE>

CMAKE_LINK_GROUP_USING_<FEATURE>_SUPPORTED

CMAKE_LINK_GROUP_USING_<FEATURE>

The value used for each of these variables is the value as set at the end of
the directory scope in which the target was created.  The usage is as follows:

If the language-specific
CMAKE_<LANG>_LINK_GROUP_USING_<FEATURE>_SUPPORTED variable
is true, the feature must be defined by the corresponding
CMAKE_<LANG>_LINK_GROUP_USING_<FEATURE> variable.

If no language-specific feature is supported, then the
CMAKE_LINK_GROUP_USING_<FEATURE>_SUPPORTED variable must be
true and the feature must be defined by the corresponding
CMAKE_LINK_GROUP_USING_<FEATURE> variable.

The LINK_GROUP generator expression is compatible with the
LINK_LIBRARY generator expression. The libraries involved in a
group can be specified using the LINK_LIBRARY generator expression.

Each target or external library involved in the link step is allowed to be
part of multiple groups, but only if all the groups involved specify the
same feature.  Such groups will not be merged on the linker command line,
the individual groups will still be preserved.  Mixing different group
features for the same target or library is forbidden.

add_library(lib1 ...)
add_library(lib2 ...)
add_library(lib3 ...)
add_library(lib4 ...)
add_library(lib5 ...)

target_link_libraries(lib3 PUBLIC  "$<LINK_GROUP:feature1,lib1,lib2>")
target_link_libraries(lib4 PRIVATE "$<LINK_GROUP:feature1,lib1,lib3>")
# lib4 will be linked with the groups {lib1,lib2} and {lib1,lib3}.
# Both groups specify the same feature, so this is fine.

target_link_libraries(lib5 PRIVATE "$<LINK_GROUP:feature2,lib1,lib3>")
# An error will be raised here because both lib1 and lib3 are part of two
# groups with different features.

When a target or an external library is involved in the link step as part of
a group and also as not part of any group, any occurrence of the non-group
link item will be replaced by the groups it belongs to.

add_library(lib1 ...)
add_library(lib2 ...)
add_library(lib3 ...)
add_library(lib4 ...)

target_link_libraries(lib3 PUBLIC lib1)

target_link_libraries(lib4 PRIVATE lib3 "$<LINK_GROUP:feature1,lib1,lib2>")
# lib4 will only be linked with lib3 and the group {lib1,lib2}

Because lib1 is part of the group defined for lib4, that group then
gets applied back to the use of lib1 for lib3.  The end result will
be as though the linking relationship for lib3 had been specified as:

target_link_libraries(lib3 PUBLIC "$<LINK_GROUP:feature1,lib1,lib2>")

Be aware that the precedence of the group over the non-group link item can
result in circular dependencies between groups.  If this occurs, a fatal
error is raised because circular dependencies are not allowed for groups.

add_library(lib1A ...)
add_library(lib1B ...)
add_library(lib2A ...)
add_library(lib2B ...)
add_library(lib3 ...)

# Non-group linking relationships, these are non-circular so far
target_link_libraries(lib1A PUBLIC lib2A)
target_link_libraries(lib2B PUBLIC lib1B)

# The addition of these groups creates circular dependencies
target_link_libraries(lib3 PRIVATE
  "$<LINK_GROUP:feat,lib1A,lib1B>"
  "$<LINK_GROUP:feat,lib2A,lib2B>"
)

Because of the groups defined for lib3, the linking relationships for
lib1A and lib2B effectively get expanded to the equivalent of:

target_link_libraries(lib1A PUBLIC "$<LINK_GROUP:feat,lib2A,lib2B>")
target_link_libraries(lib2B PUBLIC "$<LINK_GROUP:feat,lib1A,lib1B>")

This creates a circular dependency between groups:
lib1A --> lib2B --> lib1A.

The following limitations should also be noted:

The library-list can specify CMake targets or libraries.
Any CMake target of type OBJECT
or INTERFACE will ignore the feature aspect
of the expression and instead be linked in the standard way.

The $<LINK_GROUP:...> generator expression can only be used to
specify link libraries.  In practice, this means it can appear in the
LINK_LIBRARIES, INTERFACE_LINK_LIBRARIES,and
INTERFACE_LINK_LIBRARIES_DIRECT target properties, and be
specified in target_link_libraries() and link_libraries()
commands.

If a $<LINK_GROUP:...> generator expression appears in the
INTERFACE_LINK_LIBRARIES property of a target, it will be
included in the imported target generated by a install(EXPORT)
command.  It is the responsibility of the environment consuming this
import to define the link feature used by this expression.

Link Context¶

$<LINK_ONLY:...>¶

New in version 3.1.

Content of ..., except while collecting Transitive Usage Requirements,
in which case it is the empty string.  This is intended for use in an
INTERFACE_LINK_LIBRARIES target property, typically populated
via the target_link_libraries() command, to specify private link
dependencies without other usage requirements such as include directories or
compile options.

New in version 3.24: LINK_ONLY may also be used in a LINK_LIBRARIES target
property.  See policy CMP0131.

$<DEVICE_LINK:list>¶

New in version 3.18.

Returns the list if it is the device link step, an empty list otherwise.
The device link step is controlled by CUDA_SEPARABLE_COMPILATION
and CUDA_RESOLVE_DEVICE_SYMBOLS properties and
policy CMP0105. This expression can only be used to specify link
options.

$<HOST_LINK:list>¶

New in version 3.18.

Returns the list if it is the normal link step, an empty list otherwise.
This expression is mainly useful when a device link step is also involved
(see $<DEVICE_LINK:list> generator expression). This expression can
only be used to specify link options.

Target-Dependent Expressions¶

These queries refer to a target tgt. Unless otherwise stated, this can
be any runtime artifact, namely:

An executable target created by add_executable().

A shared library target (.so, .dll but not their .lib import
library) created by add_library().

A static library target created by add_library().

In the following, the phrase "the tgt filename" means the name of the
tgt binary file. This has to be distinguished from the phrase
"the target name", which is just the string tgt.

$<TARGET_EXISTS:tgt>¶

New in version 3.12.

1 if tgt exists as a CMake target, else 0.

$<TARGET_NAME_IF_EXISTS:tgt>¶

New in version 3.12.

The target name tgt if the target exists, an empty string otherwise.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_NAME:...>¶

Marks ... as being the name of a target.  This is required if exporting
targets to multiple dependent export sets.  The ... must be a literal
name of a target, it may not contain generator expressions.

$<TARGET_PROPERTY:tgt,prop>¶

Value of the property prop on the target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

Changed in version 3.26: When encountered during evaluation of Transitive Usage Requirements,
typically in an INTERFACE_* target property, lookup of the tgt
name occurs in the directory of the target specifying the requirement,
rather than the directory of the consuming target for which the
expression is being evaluated.

$<TARGET_PROPERTY:prop>¶

Value of the property prop on the target for which the expression
is being evaluated. Note that for generator expressions in
Transitive Usage Requirements this is the consuming target rather
than the target specifying the requirement.

$<TARGET_OBJECTS:tgt>¶

New in version 3.1.

List of objects resulting from building tgt.  This would typically be
used on object library targets.

$<TARGET_POLICY:policy>¶

1 if the policy was NEW when the 'head' target was created,
else 0.  If the policy was not set, the warning message for the policy
will be emitted. This generator expression only works for a subset of
policies.

$<TARGET_FILE:tgt>¶

Full path to the tgt binary file.

Note that tgt is not added as a dependency of the target this
expression is evaluated on, unless the expression is being used in
add_custom_command() or add_custom_target().

$<TARGET_FILE_BASE_NAME:tgt>¶

New in version 3.15.

Base name of tgt, i.e. $<TARGET_FILE_NAME:tgt> without prefix and
suffix.
For example, if the tgt filename is libbase.so, the base name is base.

See also the OUTPUT_NAME, ARCHIVE_OUTPUT_NAME,
LIBRARY_OUTPUT_NAME and RUNTIME_OUTPUT_NAME
target properties and their configuration specific variants
OUTPUT_NAME_<CONFIG>, ARCHIVE_OUTPUT_NAME_<CONFIG>,
LIBRARY_OUTPUT_NAME_<CONFIG> and
RUNTIME_OUTPUT_NAME_<CONFIG>.

The <CONFIG>_POSTFIX and DEBUG_POSTFIX target
properties can also be considered.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_FILE_PREFIX:tgt>¶

New in version 3.15.

Prefix of the tgt filename (such as lib).

See also the PREFIX target property.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_FILE_SUFFIX:tgt>¶

New in version 3.15.

Suffix of the tgt filename (extension such as .so or .exe).

See also the SUFFIX target property.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_FILE_NAME:tgt>¶

The tgt filename.

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_FILE_DIR:tgt>¶

Directory of the tgt binary file.

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_IMPORT_FILE:tgt>¶

New in version 3.27.

Full path to the linker import file. On DLL platforms, it would be the
.lib file. For executables on AIX, and for shared libraries on macOS,
it could be, respectively, the .imp or .tbd import file,
depending on the value of the ENABLE_EXPORTS property.

This expands to an empty string when there is no import file associated
with the target.

$<TARGET_IMPORT_FILE_BASE_NAME:tgt>¶

New in version 3.27.

Base name of the linker import file of the target tgt without prefix or
suffix. For example, if the target file name is libbase.tbd, the base
name is base.

See also the OUTPUT_NAME and ARCHIVE_OUTPUT_NAME
target properties and their configuration specific variants
OUTPUT_NAME_<CONFIG> and ARCHIVE_OUTPUT_NAME_<CONFIG>.

The <CONFIG>_POSTFIX and DEBUG_POSTFIX target
properties can also be considered.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_IMPORT_FILE_PREFIX:tgt>¶

New in version 3.27.

Prefix of the import file of the target tgt.

See also the IMPORT_PREFIX target property.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_IMPORT_FILE_SUFFIX:tgt>¶

New in version 3.27.

Suffix of the import file of the target tgt.

The suffix corresponds to the file extension (such as .lib or .tbd).

See also the IMPORT_SUFFIX target property.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_IMPORT_FILE_NAME:tgt>¶

New in version 3.27.

Name of the import file of the target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_IMPORT_FILE_DIR:tgt>¶

New in version 3.27.

Directory of the import file of the target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_FILE:tgt>¶

File used when linking to the tgt target.  This will usually
be the library that tgt represents (.a, .lib, .so),
but for a shared library on DLL platforms, it would be the .lib
import library associated with the DLL.

New in version 3.27: On macOS, it could be the .tbd import file associated with the shared
library, depending on the value of the ENABLE_EXPORTS property.

This generator expression is equivalent to
$<TARGET_LINKER_LIBRARY_FILE> or
$<TARGET_LINKER_IMPORT_FILE> generator expressions, depending on the
characteristics of the target and the platform.

$<TARGET_LINKER_FILE_BASE_NAME:tgt>¶

New in version 3.15.

Base name of file used to link the target tgt, i.e.
$<TARGET_LINKER_FILE_NAME:tgt> without prefix and suffix. For
example, if target file name is libbase.a, the base name is base.

See also the OUTPUT_NAME, ARCHIVE_OUTPUT_NAME,
and LIBRARY_OUTPUT_NAME target properties and their configuration
specific variants OUTPUT_NAME_<CONFIG>,
ARCHIVE_OUTPUT_NAME_<CONFIG> and
LIBRARY_OUTPUT_NAME_<CONFIG>.

The <CONFIG>_POSTFIX and DEBUG_POSTFIX target
properties can also be considered.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_FILE_PREFIX:tgt>¶

New in version 3.15.

Prefix of file used to link target tgt.

See also the PREFIX and IMPORT_PREFIX target
properties.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_FILE_SUFFIX:tgt>¶

New in version 3.15.

Suffix of file used to link where tgt is the name of a target.

The suffix corresponds to the file extension (such as ".so" or ".lib").

See also the SUFFIX and IMPORT_SUFFIX target
properties.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_FILE_NAME:tgt>¶

Name of file used to link target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_LINKER_FILE_DIR:tgt>¶

Directory of file used to link target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_LINKER_LIBRARY_FILE:tgt>¶

New in version 3.27.

File used when linking o the tgt target is done using directly the
library, and not an import file. This will usually be the library that
tgt represents (.a, .so, .dylib). So, on DLL platforms, it
will be an empty string.

$<TARGET_LINKER_LIBRARY_FILE_BASE_NAME:tgt>¶

New in version 3.27.

Base name of library file used to link the target tgt, i.e.
$<TARGET_LINKER_LIBRARY_FILE_NAME:tgt> without prefix and suffix.
For example, if target file name is libbase.a, the base name is base.

See also the OUTPUT_NAME, ARCHIVE_OUTPUT_NAME,
and LIBRARY_OUTPUT_NAME target properties and their configuration
specific variants OUTPUT_NAME_<CONFIG>,
ARCHIVE_OUTPUT_NAME_<CONFIG> and
LIBRARY_OUTPUT_NAME_<CONFIG>.

The <CONFIG>_POSTFIX and DEBUG_POSTFIX target
properties can also be considered.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_LIBRARY_FILE_PREFIX:tgt>¶

New in version 3.27.

Prefix of the library file used to link target tgt.

See also the PREFIX target property.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_LIBRARY_FILE_SUFFIX:tgt>¶

New in version 3.27.

Suffix of the library file used to link target tgt.

The suffix corresponds to the file extension (such as ".a" or ".dylib").

See also the SUFFIX target property.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_LIBRARY_FILE_NAME:tgt>¶

New in version 3.27.

Name of the library file used to link target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_LIBRARY_FILE_DIR:tgt>¶

New in version 3.27.

Directory of the library file used to link target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_IMPORT_FILE:tgt>¶

New in version 3.27.

File used when linking to the tgt target is done using an import
file.  This will usually be the import file that tgt represents
(.lib, .tbd). So, when no import file is involved in the link step,
an empty string is returned.

$<TARGET_LINKER_IMPORT_FILE_BASE_NAME:tgt>¶

New in version 3.27.

Base name of the import file used to link the target tgt, i.e.
$<TARGET_LINKER_IMPORT_FILE_NAME:tgt> without prefix and suffix.
For example, if target file name is libbase.tbd, the base name is base.

See also the OUTPUT_NAME and ARCHIVE_OUTPUT_NAME,
target properties and their configuration
specific variants OUTPUT_NAME_<CONFIG> and
ARCHIVE_OUTPUT_NAME_<CONFIG>.

The <CONFIG>_POSTFIX and DEBUG_POSTFIX target
properties can also be considered.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_IMPORT_FILE_PREFIX:tgt>¶

New in version 3.27.

Prefix of the import file used to link target tgt.

See also the IMPORT_PREFIX target property.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_IMPORT_FILE_SUFFIX:tgt>¶

New in version 3.27.

Suffix of the import file used to link target tgt.

The suffix corresponds to the file extension (such as ".lib" or ".tbd").

See also the IMPORT_SUFFIX target property.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_IMPORT_FILE_NAME:tgt>¶

New in version 3.27.

Name of the import file used to link target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_LINKER_IMPORT_FILE_DIR:tgt>¶

New in version 3.27.

Directory of the import file used to link target tgt.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_SONAME_FILE:tgt>¶

File with soname (.so.3) where tgt is the name of a target.

$<TARGET_SONAME_FILE_NAME:tgt>¶

Name of file with soname (.so.3).

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_SONAME_FILE_DIR:tgt>¶

Directory of file with soname (.so.3).

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_SONAME_IMPORT_FILE:tgt>¶

New in version 3.27.

Import file with soname (.3.tbd) where tgt is the name of a target.

$<TARGET_SONAME_IMPORT_FILE_NAME:tgt>¶

New in version 3.27.

Name of the import file with soname (.3.tbd).

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_SONAME_IMPORT_FILE_DIR:tgt>¶

New in version 3.27.

Directory of the import file with soname (.3.tbd).

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_PDB_FILE:tgt>¶

New in version 3.1.

Full path to the linker generated program database file (.pdb)
where tgt is the name of a target.

See also the PDB_NAME and PDB_OUTPUT_DIRECTORY
target properties and their configuration specific variants
PDB_NAME_<CONFIG> and PDB_OUTPUT_DIRECTORY_<CONFIG>.

$<TARGET_PDB_FILE_BASE_NAME:tgt>¶

New in version 3.15.

Base name of the linker generated program database file (.pdb)
where tgt is the name of a target.

The base name corresponds to the target PDB file name (see
$<TARGET_PDB_FILE_NAME:tgt>) without prefix and suffix. For example,
if target file name is base.pdb, the base name is base.

See also the PDB_NAME target property and its configuration
specific variant PDB_NAME_<CONFIG>.

The <CONFIG>_POSTFIX and DEBUG_POSTFIX target
properties can also be considered.

Note that tgt is not added as a dependency of the target this
expression is evaluated on.

$<TARGET_PDB_FILE_NAME:tgt>¶

New in version 3.1.

Name of the linker generated program database file (.pdb).

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_PDB_FILE_DIR:tgt>¶

New in version 3.1.

Directory of the linker generated program database file (.pdb).

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_BUNDLE_DIR:tgt>¶

New in version 3.9.

Full path to the bundle directory (/path/to/my.app,
/path/to/my.framework, or /path/to/my.bundle),
where tgt is the name of a target.

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_BUNDLE_DIR_NAME:tgt>¶

New in version 3.24.

Name of the bundle directory (my.app, my.framework, or
my.bundle), where tgt is the name of a target.

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_BUNDLE_CONTENT_DIR:tgt>¶

New in version 3.9.

Full path to the bundle content directory where tgt is the name of a
target.  For the macOS SDK it leads to /path/to/my.app/Contents,
/path/to/my.framework, or /path/to/my.bundle/Contents.
For all other SDKs (e.g. iOS) it leads to /path/to/my.app,
/path/to/my.framework, or /path/to/my.bundle due to the flat
bundle structure.

Note that tgt is not added as a dependency of the target this
expression is evaluated on (see policy CMP0112).

$<TARGET_RUNTIME_DLLS:tgt>¶

New in version 3.21.

List of DLLs that the target depends on at runtime. This is determined by
the locations of all the SHARED targets in the target's transitive
dependencies. If only the directories of the DLLs are needed, see the
TARGET_RUNTIME_DLL_DIRS generator expression.
Using this generator expression on targets other than
executables, SHARED libraries, and MODULE libraries is an error.
On non-DLL platforms, this expression always evaluates to an empty string.

This generator expression can be used to copy all of the DLLs that a target
depends on into its output directory in a POST_BUILD custom command using
the cmake -E copy -t command. For example:

find_package(foo CONFIG REQUIRED) # package generated by install(EXPORT)

add_executable(exe main.c)
target_link_libraries(exe PRIVATE foo::foo foo::bar)
add_custom_command(TARGET exe POST_BUILD
  COMMAND ${CMAKE_COMMAND} -E copy -t $<TARGET_FILE_DIR:exe> $<TARGET_RUNTIME_DLLS:exe>
  COMMAND_EXPAND_LISTS
)

Note

Imported Targets are supported only if they know the location
of their .dll files.  An imported SHARED library must have
IMPORTED_LOCATION set to its .dll file.  See the
add_library imported libraries
section for details.  Many Find Modules produce imported targets
with the UNKNOWN type and therefore will be ignored.

On platforms that support runtime paths (RPATH), refer to the
INSTALL_RPATH target property.
On Apple platforms, refer to the INSTALL_NAME_DIR target property.

$<TARGET_RUNTIME_DLL_DIRS:tgt>¶

New in version 3.27.

List of the directories which contain the DLLs that the target depends on at
runtime (see TARGET_RUNTIME_DLLS). This is determined by
the locations of all the SHARED targets in the target's transitive
dependencies. Using this generator expression on targets other than
executables, SHARED libraries, and MODULE libraries is an error.
On non-DLL platforms, this expression always evaluates to an empty string.

This generator expression can e.g. be used to create a batch file using
file(GENERATE) which sets the PATH environment variable accordingly.

Export And Install Expressions¶

$<INSTALL_INTERFACE:...>¶

Content of ... when the property is exported using
install(EXPORT), and empty otherwise.

$<BUILD_INTERFACE:...>¶

Content of ... when the property is exported using export(), or
when the target is used by another target in the same buildsystem. Expands to
the empty string otherwise.

$<BUILD_LOCAL_INTERFACE:...>¶

New in version 3.26.

Content of ... when the target is used by another target in the same
buildsystem. Expands to the empty string otherwise.

$<INSTALL_PREFIX>¶

Content of the install prefix when the target is exported via
install(EXPORT), or when evaluated in the
INSTALL_NAME_DIR property or the INSTALL_NAME_DIR argument of
install(RUNTIME_DEPENDENCY_SET), and empty otherwise.

Changed in version 3.27: Evaluates to the content of the install prefix
in the code argument of install(CODE) or
the file argument of install(SCRIPT).

Multi-level Expression Evaluation¶

$<GENEX_EVAL:expr>¶

New in version 3.12.

Content of expr evaluated as a generator expression in the current
context. This enables consumption of generator expressions whose
evaluation results itself in generator expressions.

$<TARGET_GENEX_EVAL:tgt,expr>¶

New in version 3.12.

Content of expr evaluated as a generator expression in the context of
tgt target. This enables consumption of custom target properties that
themselves contain generator expressions.

Having the capability to evaluate generator expressions is very useful when
you want to manage custom properties supporting generator expressions.
For example:

add_library(foo ...)

set_property(TARGET foo PROPERTY
  CUSTOM_KEYS $<$<CONFIG:DEBUG>:FOO_EXTRA_THINGS>
)

add_custom_target(printFooKeys
  COMMAND ${CMAKE_COMMAND} -E echo $<TARGET_PROPERTY:foo,CUSTOM_KEYS>
)

This naive implementation of the printFooKeys custom command is wrong
because CUSTOM_KEYS target property is not evaluated and the content
is passed as is (i.e. $<$<CONFIG:DEBUG>:FOO_EXTRA_THINGS>).

To have the expected result (i.e. FOO_EXTRA_THINGS if config is
Debug), it is required to evaluate the output of
$<TARGET_PROPERTY:foo,CUSTOM_KEYS>:

add_custom_target(printFooKeys
  COMMAND ${CMAKE_COMMAND} -E
    echo $<TARGET_GENEX_EVAL:foo,$<TARGET_PROPERTY:foo,CUSTOM_KEYS>>
)

Escaped Characters¶

These expressions evaluate to specific string literals. Use them in place of
the actual string literal where you need to prevent them from having their
special meaning.

$<ANGLE-R>¶

A literal >. Used for example to compare strings that contain a >.

$<COMMA>¶

A literal ,. Used for example to compare strings which contain a ,.

$<SEMICOLON>¶

A literal ;. Used to prevent list expansion on an argument with ;.

Deprecated Expressions¶

$<CONFIGURATION>¶

Configuration name. Deprecated since CMake 3.0. Use CONFIG instead.

Table of Contents

cmake-generator-expressions(7)

Introduction

Whitespace And Quoting

Debugging

Generator Expression Reference

Conditional Expressions

Logical Operators

Primary Comparison Expressions

String Comparisons

Version Comparisons

String Transformations

List Expressions

List Comparisons

List Queries

List Transformations

List Ordering

Path Expressions

Path Comparisons

Path Queries

Path Decomposition

Path Transformations

Shell Paths

Configuration Expressions

Toolchain And Language Expressions

Platform

Compiler Version

Compiler Language And ID

Compile Features

Compile Context

Linker Language And ID

Link Features

Link Context

Target-Dependent Expressions

Export And Install Expressions

Multi-level Expression Evaluation

Escaped Characters

Deprecated Expressions

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Contents

cmake-generators(7)

Introduction

CMake Generators

Command-Line Build Tool Generators

Makefile Generators

Ninja Generators

IDE Build Tool Generators

Visual Studio Generators

Other Generators

Extra Generators

Introduction¶

A CMake Generator is responsible for writing the input files for
a native build system.  Exactly one of the CMake Generators must be
selected for a build tree to determine what native build system is to
be used.  Optionally one of the Extra Generators may be selected
as a variant of some of the Command-Line Build Tool Generators to
produce project files for an auxiliary IDE.

CMake Generators are platform-specific so each may be available only
on certain platforms.  The cmake(1) command-line tool
--help output lists available generators on the
current platform.  Use its -G option to specify the
generator for a new build tree. The cmake-gui(1) offers
interactive selection of a generator when creating a new build tree.

CMake Generators¶

Command-Line Build Tool Generators¶

These generators support command-line build tools.  In order to use them,
one must launch CMake from a command-line prompt whose environment is
already configured for the chosen compiler and build tool.

Makefile Generators¶

Borland Makefiles

MSYS Makefiles

MinGW Makefiles

NMake Makefiles

NMake Makefiles JOM

Unix Makefiles

Watcom WMake

Ninja Generators¶

Ninja

Ninja Multi-Config

IDE Build Tool Generators¶

These generators support Integrated Development Environment (IDE)
project files.  Since the IDEs configure their own environment
one may launch CMake from any environment.

Visual Studio Generators¶

Visual Studio 6

Visual Studio 7

Visual Studio 7 .NET 2003

Visual Studio 8 2005

Visual Studio 9 2008

Visual Studio 10 2010

Visual Studio 11 2012

Visual Studio 12 2013

Visual Studio 14 2015

Visual Studio 15 2017

Visual Studio 16 2019

Visual Studio 17 2022

Other Generators¶

Green Hills MULTI

Xcode

Extra Generators¶

Deprecated since version 3.27: Support for "Extra Generators" is deprecated and will be removed from
a future version of CMake.  IDEs may use the cmake-file-api(7)
to view CMake-generated project build trees.

Some of the CMake Generators listed in the cmake(1)
command-line tool --help output may have
variants that specify an extra generator for an auxiliary IDE tool.
Such generator names have the form <extra-generator> - <main-generator>.
The following extra generators are known to CMake.

CodeBlocks

CodeLite

Eclipse CDT4

Kate

Sublime Text 2

Table of Contents

cmake-generators(7)

Introduction

CMake Generators

Command-Line Build Tool Generators

Makefile Generators

Ninja Generators

IDE Build Tool Generators

Visual Studio Generators

Other Generators

Extra Generators

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cmake-generator-expressions(7)

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cmake-modules(7)

cmake-modules(7)¶

The modules listed here are part of the CMake distribution.
Projects may provide further modules; their location(s)
can be specified in the CMAKE_MODULE_PATH variable.

Utility Modules¶

These modules are loaded using the include() command.

AndroidTestUtilities

BundleUtilities

CheckCCompilerFlag

CheckCompilerFlag

CheckCSourceCompiles

CheckCSourceRuns

CheckCXXCompilerFlag

CheckCXXSourceCompiles

CheckCXXSourceRuns

CheckCXXSymbolExists

CheckFortranCompilerFlag

CheckFortranFunctionExists

CheckFortranSourceCompiles

CheckFortranSourceRuns

CheckFunctionExists

CheckIncludeFileCXX

CheckIncludeFile

CheckIncludeFiles

CheckIPOSupported

CheckLanguage

CheckLibraryExists

CheckLinkerFlag

CheckOBJCCompilerFlag

CheckOBJCSourceCompiles

CheckOBJCSourceRuns

CheckOBJCXXCompilerFlag

CheckOBJCXXSourceCompiles

CheckOBJCXXSourceRuns

CheckPIESupported

CheckPrototypeDefinition

CheckSourceCompiles

CheckSourceRuns

CheckStructHasMember

CheckSymbolExists

CheckTypeSize

CheckVariableExists

CMakeAddFortranSubdirectory

CMakeBackwardCompatibilityCXX

CMakeDependentOption

CMakeFindDependencyMacro

CMakeFindFrameworks

CMakeFindPackageMode

CMakeGraphVizOptions

CMakePackageConfigHelpers

CMakePrintHelpers

CMakePrintSystemInformation

CMakePushCheckState

CMakeVerifyManifest

CPack

CPackComponent

CPackIFW

CPackIFWConfigureFile

CSharpUtilities

CTest

CTestCoverageCollectGCOV

CTestScriptMode

CTestUseLaunchers

DeployQt4

ExternalData

ExternalProject

FeatureSummary

FetchContent

FindPackageHandleStandardArgs

FindPackageMessage

FortranCInterface

GenerateExportHeader

GNUInstallDirs

GoogleTest

InstallRequiredSystemLibraries

ProcessorCount

SelectLibraryConfigurations

SquishTestScript

TestForANSIForScope

TestForANSIStreamHeaders

TestForSSTREAM

TestForSTDNamespace

UseEcos

UseJava

UseSWIG

UsewxWidgets

Find Modules¶

These modules search for third-party software.
They are normally called through the find_package() command.

FindALSA

FindArmadillo

FindASPELL

FindAVIFile

FindBacktrace

FindBISON

FindBLAS

FindBoost

FindBullet

FindBZip2

FindCABLE

FindCoin3D

FindCUDAToolkit

FindCups

FindCURL

FindCurses

FindCVS

FindCxxTest

FindCygwin

FindDCMTK

FindDevIL

FindDoxygen

FindEnvModules

FindEXPAT

FindFLEX

FindFLTK

FindFLTK2

FindFontconfig

FindFreetype

FindGCCXML

FindGDAL

FindGettext

FindGIF

FindGit

FindGLEW

FindGLUT

FindGnuplot

FindGnuTLS

FindGSL

FindGTest

FindGTK

FindGTK2

FindHDF5

FindHg

FindHSPELL

FindHTMLHelp

FindIce

FindIconv

FindIcotool

FindICU

FindImageMagick

FindIntl

FindJasper

FindJava

FindJNI

FindJPEG

FindKDE3

FindKDE4

FindLAPACK

FindLATEX

FindLibArchive

FindLibinput

FindLibLZMA

FindLibXml2

FindLibXslt

FindLTTngUST

FindLua

FindLua50

FindLua51

FindMatlab

FindMFC

FindMotif

FindMPEG

FindMPEG2

FindMPI

FindMsys

FindODBC

FindOpenACC

FindOpenAL

FindOpenCL

FindOpenGL

FindOpenMP

FindOpenSceneGraph

FindOpenSP

FindOpenSSL

FindOpenThreads

Findosg

Findosg_functions

FindosgAnimation

FindosgDB

FindosgFX

FindosgGA

FindosgIntrospection

FindosgManipulator

FindosgParticle

FindosgPresentation

FindosgProducer

FindosgQt

FindosgShadow

FindosgSim

FindosgTerrain

FindosgText

FindosgUtil

FindosgViewer

FindosgVolume

FindosgWidget

FindPatch

FindPerl

FindPerlLibs

FindPHP4

FindPhysFS

FindPike

FindPkgConfig

FindPNG

FindPostgreSQL

FindProducer

FindProtobuf

FindPython

FindPython2

FindPython3

FindQt3

FindQt4

FindQuickTime

FindRTI

FindRuby

FindSDL

FindSDL_image

FindSDL_gfx

FindSDL_mixer

FindSDL_net

FindSDL_sound

FindSDL_ttf

FindSelfPackers

FindSquish

FindSQLite3

FindSubversion

FindSWIG

FindTCL

FindTclsh

FindTclStub

FindThreads

FindTIFF

FindVulkan

FindWget

FindWish

FindwxWidgets

FindX11

FindXalanC

FindXCTest

FindXercesC

FindXMLRPC

FindZLIB

Deprecated Modules¶

Deprecated Utility Modules¶

AddFileDependencies

CMakeDetermineVSServicePack

CMakeExpandImportedTargets

CMakeForceCompiler

CMakeParseArguments

Dart

Documentation

GetPrerequisites

MacroAddFileDependencies

TestBigEndian

TestCXXAcceptsFlag

UseJavaClassFilelist

UseJavaSymlinks

UsePkgConfig

Use_wxWindows

WriteBasicConfigVersionFile

WriteCompilerDetectionHeader

Deprecated Find Modules¶

FindCUDA

FindDart

FindITK

FindPythonInterp

FindPythonLibs

FindQt

FindUnixCommands

FindVTK

FindwxWindows

Legacy CPack Modules¶

These modules used to be mistakenly exposed to the user, and have been moved
out of user visibility. They are for CPack internal use, and should never be
used directly.

CPackArchive

CPackBundle

CPackCygwin

CPackDeb

CPackDMG

CPackFreeBSD

CPackNSIS

CPackNuGet

CPackProductBuild

CPackRPM

CPackWIX

Table of Contents

cmake-modules(7)

Utility Modules

Find Modules

Deprecated Modules

Deprecated Utility Modules

Deprecated Find Modules

Legacy CPack Modules

Previous topic

cmake-language(7)

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AndroidTestUtilities

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