Help/manual/cmake-generator-expressions.7.rst
.. cmake-manual-description: CMake Generator Expressions
cmake-generator-expressions(7)
.. only:: html
.. contents::
Generator expressions are evaluated during build system generation to produce
information specific to each build configuration. They have the form
$<...>. For example:
.. code-block:: cmake
target_include_directories(tgt PRIVATE /opt/include/$<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 :prop_tgt:LINK_LIBRARIES, :prop_tgt:INCLUDE_DIRECTORIES,
:prop_tgt:COMPILE_DEFINITIONS and others. They may also be used when using
commands to populate those properties, such as :command:target_link_libraries,
:command:target_include_directories, :command: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:
.. code-block:: cmake
target_compile_definitions(tgt PRIVATE $<$<VERSION_LESS:$<CXX_COMPILER_VERSION>,4.2.0>:OLD_COMPILER> )
The above would expand to OLD_COMPILER if the
:variable:CMAKE_CXX_COMPILER_VERSION <CMAKE_<LANG>_COMPILER_VERSION> is less
than 4.2.0.
Generator expressions are typically parsed after command arguments. If a generator expression contains spaces, new lines, semicolons or other characters that may be interpreted as command argument separators, the whole expression should be surrounded by quotes when passed to a command. Failure to do so may result in the expression being split and it may no longer be recognized as a generator expression.
When using :command:add_custom_command or :command:add_custom_target,
use the VERBATIM and COMMAND_EXPAND_LISTS options to obtain robust
argument splitting and quoting.
.. code-block:: cmake
add_custom_target(run_some_tool COMMAND some_tool -I$<JOIN:$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>, -I> VERBATIM )
.. code-block:: cmake
add_custom_target(run_some_tool COMMAND some_tool "-I$<JOIN:$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>, -I>" VERBATIM )
.. code-block:: cmake
add_custom_target(run_some_tool COMMAND some_tool "-I$<JOIN:$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>,;-I>" COMMAND_EXPAND_LISTS VERBATIM )
Using variables to build up a more complex generator expression is also a good way to reduce errors and improve readability. The above example can be improved further like so:
.. code-block:: cmake
set(prop "$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>") add_custom_target(run_some_tool COMMAND some_tool "$<$BOOL:${prop}:-I$JOIN:${prop},;-I>" COMMAND_EXPAND_LISTS VERBATIM )
Finally, the above example can be expressed in a more simple and robust way using an alternate generator expression:
.. code-block:: cmake
add_custom_target(run_some_tool COMMAND some_tool "$<LIST:TRANSFORM,$<TARGET_PROPERTY:tgt,INCLUDE_DIRECTORIES>,PREPEND,-I>" COMMAND_EXPAND_LISTS VERBATIM )
For tools that expect -I's value to be a separate argument, use the
semicolon trick learned earlier:
.. code-block:: cmake
add_custom_target(run_some_tool COMMAND some_tool "$<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:
.. code-block:: cmake
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:
.. code-block:: cmake
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>" )
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 :command:message() command. One possible way
to generate debug messages is to add a custom target:
.. code-block:: cmake
add_custom_target(genexdebug COMMAND ${CMAKE_COMMAND} -E echo "$<...>")
After running :program:cmake, you can then build the genexdebug target to print
the result of the $<...> expression (i.e. run the command
:option:cmake --build ... --target genexdebug <cmake--build --target>).
Another way is to write debug messages to a file with :command:file(GENERATE):
.. code-block:: cmake
file(GENERATE OUTPUT filename CONTENT "$<...>")
.. 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 Generator Expressions:
A fundamental category of generator expressions relates to conditional logic. Two forms of conditional generator expressions are supported:
.. genex:: $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.
.. genex:: $IF:condition,true_string,false_string
.. versionadded:: 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.
.. versionadded:: 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:
.. code-block:: cmake
$<$CONFIG:Debug:DEBUG_MODE>
Boolean-like condition values other than 1 or 0 can be handled
by wrapping them with the $<BOOL:...> generator expression:
.. genex:: $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, orstring 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:
.. code-block:: cmake
$<$BOOL:${HAVE_SOME_FEATURE}:-DENABLE_SOME_FEATURE>
.. _Boolean Generator Expressions:
The common boolean logic operators are supported:
.. genex:: $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.
.. genex:: $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.
.. genex:: $NOT:condition
condition must be 0 or 1. The result of the expression is
0 if condition is 1, else 1.
.. versionadded:: 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.
.. _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.
Numeric Comparisons ^^^^^^^^^^^^^^^^^^^
.. genex:: $EQUAL:value1,value2
1 if value1 and value2 are numerically equal, else 0.
Version Comparisons ^^^^^^^^^^^^^^^^^^^
.. genex:: $<VERSION_LESS:v1,v2>
1 if v1 is a version less than v2, else 0.
.. genex:: $<VERSION_GREATER:v1,v2>
1 if v1 is a version greater than v2, else 0.
.. genex:: $<VERSION_EQUAL:v1,v2>
1 if v1 is the same version as v2, else 0.
.. genex:: $<VERSION_LESS_EQUAL:v1,v2>
.. versionadded:: 3.7
1 if v1 is a version less than or equal to v2, else 0.
.. genex:: $<VERSION_GREATER_EQUAL:v1,v2>
.. versionadded:: 3.7
1 if v1 is a version greater than or equal to v2, else 0.
Most of the expressions in this section are closely associated with the
:command:string command, providing the same capabilities, but in
the form of a generator expression.
In each of the following string-related generator expressions, the string
must not contain any commas if that generator expression expects something to
be provided after the string. For example, the expression
$<STRING:FIND,string,value> requires a value after the string.
Since a comma is used to separate the string and the value, the
string cannot itself contain a comma. This restriction does not apply to
the :command:string command, it is specific to the string-handling generator
expressions only. The :genex:$<COMMA> generator expression can be used to
specify a comma as part of the arguments of the string-related generator
expressions.
.. _String Comparisons Generator Expressions:
String Comparisons ^^^^^^^^^^^^^^^^^^
The comparisons are case-sensitive. For a case-insensitive comparison,
combine with a :ref:string transforming generator expression <String Transforming Generator Expressions>. For example, the following
evaluates to 1 if ${foo} is any of BAR, Bar, bar, etc.
.. code-block:: cmake
$<STREQUAL:$<STRING:TOUPPER,${foo}>,BAR>
.. genex:: $STREQUAL:string1,string2
1 if string1 and string2 are lexicographically equal, else 0.
.. genex:: $STRLESS:string1,string2
.. versionadded:: 4.3
1 if string1 is lexicographically less than string2, else 0.
.. genex:: $STRGREATER:string1,string2
.. versionadded:: 4.3
1 if string1 is lexicographically greater than string2, else
0.
.. genex:: $<STRLESS_EQUAL:string1,string2>
.. versionadded:: 4.3
1 if string1 is lexicographically less than or equal to string2,
else 0.
.. genex:: $<STRGREATER_EQUAL:string1,string2>
.. versionadded:: 4.3
1 if string1 is lexicographically greater than or equal to
string2, else 0.
.. _String Queries Generator Expressions:
String Queries ^^^^^^^^^^^^^^
.. genex:: $STRING:LENGTH,string
.. versionadded:: 4.3
The given string's length in bytes. Note that this means, if string
contains multi-byte characters, the result will not be the number of
characters.
.. genex:: $STRING:SUBSTRING,string,begin,length
.. versionadded:: 4.3
The substring of the given string. If length is -1 or greater
than the string length the remainder of the string starting at begin
will be returned.
Both begin and length are counted in bytes, so care must
be exercised if string could contain multi-byte characters.
.. genex:: $STRING:FIND,string[,FROM:(BEGIN|END)],substring
.. versionadded:: 4.3
The position where the given substring was found in the supplied
string. If the substring is not found, a position of -1 is returned.
The FROM: option defines how the search will be done:
BEGIN
The search will start at the beginning of the string. This the default.
END
The search will start from the end of the string.
The $<STRING:FIND> generator expression treats all strings as ASCII-only
characters. The index returned will also be counted in bytes, so strings
containing multi-byte characters may lead to unexpected results.
.. genex:: $STRING:MATCH,string[,SEEK:(ONCE|ALL)],regular_expression
.. versionadded:: 4.3
Match, in the string, the regular_expression.
The SEEK: option specifies the match behavior:
ONCE
Match only the first occurrence. This is the default.
ALL
Match as many times as possible and return the matches as a list.
See the :ref:Regular expressions specification <Regex Specification> for
the syntax of the regular_expression parameter.
.. _String Generating Generator Expressions:
String Generations ^^^^^^^^^^^^^^^^^^
.. genex:: $STRING:JOIN,glue,input[,input]...
.. versionadded:: 4.3
Join all the input arguments together using the glue string.
.. genex:: $STRING:ASCII,number[,number]...
.. versionadded:: 4.3
Convert all numbers, in the range 1-255, into corresponding ASCII characters. Any number outside this range will raise an error.
.. genex:: $STRING:TIMESTAMP[,(UTC|format)]...
.. versionadded:: 4.3
Produce a string representation of the current date and/or time.
If the generator expression is unable to obtain a timestamp, the result will
be the empty string "".
The optional UTC flag requests the current date/time representation to
be in Coordinated Universal Time (UTC) rather than local time.
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.
The optional <format> may contain the following format specifiers:
%%
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
Abbreviated month name (e.g. Oct).
%B
Full month name (e.g. October).
%M
The minute of the current hour (00-59).
%s
Seconds since midnight (UTC) 1-Jan-1970 (UNIX time).
%S
The second of the current minute. 60 represents a leap second. (00-60)
%f
The microsecond of the current second (000000-999999).
%U
The week number of the current year (00-53).
%V
The ISO 8601 week number of the current year (01-53).
%w
The day of the current week. 0 is Sunday. (0-6)
%a
Abbreviated weekday name (e.g. Fri).
%A
Full weekday name (e.g. Friday).
%y
The last two digits of the current year (00-99).
%Y
The current year.
%z
The offset of the time zone from UTC, in hours and minutes,
with format +hhmm or -hhmm.
%Z
The time zone name.
Unknown format specifiers will be ignored and copied to the output as-is.
If no explicit format is given, it will default to:
%Y-%m-%dT%H:%M:%S for local time.%Y-%m-%dT%H:%M:%SZ for UTC... genex:: $STRING:RANDOM[,(LENGTH:length|ALPHABET:alphabet|RANDOM_SEED:seed)]...
.. versionadded:: 4.3
Produce a random string of ASCII characters. The possible options are:
LENGTH:length
Define the length of the string. The default length is 5 characters.
ALPHABET:alphabet
Define the characters used for the generation. The alphabet is always
interpreted as holding ASCII characters. The default alphabet is all
numbers and upper and lower case letters.
RANDOM_SEED:seed
Specify an integer which will be used to seed the random number generator.
.. genex:: $STRING:UUID,NAMESPACE:namespace,TYPE:(MD5|SHA1)[,NAME:name][,CASE:(LOWER|UPPER)]
.. versionadded:: 4.3
Create a universally unique identifier (aka GUID) as per RFC4122.
A UUID has the format xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
where each x represents an hexadecimal character.
The UUID is based on the hash of the combined values of:
NAMESPACE:namespace
namespace which has to be a valid UUID.
NAME:name
name is an arbitrary string.
TYPE:
The hash algorithm can be either:
``MD5``
Version 3 UUID.
``SHA1``
Version 5 UUID.
CASE:
Specify the case of the hexadecimal characters.
``LOWER``
Hexadecimal characters are all of lowercase. This is the default.
``UPPER``
Hexadecimal characters are all of uppercase.
.. _String Transforming Generator Expressions:
String Transformations ^^^^^^^^^^^^^^^^^^^^^^
.. genex:: $STRING:REPLACE[,(STRING|REGEX)],string,match_string,replace_string
.. versionadded:: 4.3
Replace all occurrences of match_string in the string with
replace_string.
The match_string can be of two different types:
STRING
match_string is a literal string and match will be done by simple
string comparison. This is the default.
REGEX
match_string is a regular expression. Match this regular_expression as
many times as possible and substitute the replace_string for the match
in the string.
The ``replace_string`` 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.
.. genex:: $STRING:APPEND,string,input[,input]...
.. versionadded:: 4.3
Append all the input arguments to the string.
.. genex:: $STRING:PREPEND,string,input[,input]...
.. versionadded:: 4.3
Prepend all the input arguments to the string.
.. genex:: $STRING:TOLOWER,string
.. versionadded:: 4.3
Content of string converted to lower case.
.. genex:: $STRING:TOUPPER,string
.. versionadded:: 4.3
Content of string converted to upper case.
.. genex:: $STRING:STRIP,SPACES,string
.. versionadded:: 4.3
Remove the specified elements from the string. The possible options are:
SPACES
Remove the leading and trailing spaces of the string.
.. genex:: $STRING:QUOTE,REGEX,string
.. versionadded:: 4.3
Escape the specified elements of the string. The possible options are:
REGEX
Escape all characters that have special meaning in a regular expressions,
such that the string can be used as part of a regular expression to
match the input literally.
.. genex:: $STRING:HEX,string
.. versionadded:: 4.3
Convert each byte in the string to its hexadecimal representation.
Letters in the result (a through f) are in lowercase.
.. genex:: $STRING:HASH,string,ALGORITHM:algorithm
.. versionadded:: 4.3
Compute a cryptographic hash of the string. The supported algorithm
names, as specified by the ALGORITHM: option 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.
.. genex:: $STRING:MAKE_C_IDENTIFIER,string
.. versionadded:: 4.3
Convert each non-alphanumeric character in the string to an underscore.
If the first character of the string is a digit, an underscore will also
be prepended.
.. genex:: $<LOWER_CASE:string>
Content of string converted to lower case.
.. genex:: $<UPPER_CASE:string>
Content of string converted to upper case.
.. genex:: $<MAKE_C_IDENTIFIER:string>
Content of string converted to a C identifier. The conversion follows
the same behavior as :command:string(MAKE_C_IDENTIFIER).
Most of the expressions in this section are closely associated with the
:command: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
:command:list command, it is specific to the list-handling generator
expressions only.
.. _GenEx List Comparisons:
List Comparisons ^^^^^^^^^^^^^^^^
.. genex:: $<IN_LIST:string,list>
.. versionadded:: 3.12
1 if string is an item in the semicolon-separated list, else 0.
It uses case-sensitive comparisons.
.. _GenEx List Queries:
List Queries ^^^^^^^^^^^^
.. genex:: $LIST:LENGTH,list
.. versionadded:: 3.27
The number of items in the list.
.. genex:: $LIST:GET,list,index,...
.. versionadded:: 3.27
Expands to the list of items specified by indices from the list.
.. genex:: $LIST:SUBLIST,list,begin,length
.. versionadded:: 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.
.. genex:: $LIST:FIND,list,value
.. versionadded:: 3.27
The index of the first item in list with the specified value,
or -1 if value is not in the list.
.. _GenEx List Transformations:
List Transformations ^^^^^^^^^^^^^^^^^^^^
.. _GenEx LIST-JOIN:
.. genex:: $LIST:JOIN,list,glue
.. versionadded:: 3.27
Converts list to a single string with the content of the glue string
inserted between each item. This is conceptually the same operation as
:genex:$<JOIN:list,glue>, but the two have different behavior with regard
to empty items. $<LIST:JOIN,list,glue> preserves all empty items,
whereas :genex:$<JOIN:list,glue> drops all empty items from the list.
.. genex:: $LIST:APPEND,list,item,...
.. versionadded:: 3.27
The list with each item appended. Multiple items should be
separated by commas.
.. genex:: $LIST:PREPEND,list,item,...
.. versionadded:: 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.
.. genex:: $LIST:INSERT,list,index,item,...
.. versionadded:: 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.
.. genex:: $LIST:POP_BACK,list
.. versionadded:: 3.27
The list with the last item removed.
.. genex:: $LIST:POP_FRONT,list
.. versionadded:: 3.27
The list with the first item removed.
.. genex:: $LIST:REMOVE_ITEM,list,value,...
.. versionadded:: 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.
.. genex:: $LIST:REMOVE_AT,list,index,...
.. versionadded:: 3.27
The list with the item at each given index removed.
.. _GenEx LIST-REMOVE_DUPLICATES:
.. genex:: $LIST:REMOVE_DUPLICATES,list
.. versionadded:: 3.27
The list with all duplicated items removed. The relative order of
items is preserved, but if duplicates are encountered, only the first
instance is preserved. The result is the same as
:genex:$<REMOVE_DUPLICATES:list>.
.. _GenEx LIST-FILTER:
.. genex:: $LIST:FILTER,list,INCLUDE|EXCLUDE,regex
.. versionadded:: 3.27
A list of items from the list which match (INCLUDE) or do not match
(EXCLUDE) the regular expression regex. The result is the same as
:genex:$<FILTER:list,INCLUDE|EXCLUDE,regex>.
.. genex:: $LIST:TRANSFORM,list,ACTION[,SELECTOR]
.. versionadded:: 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
:command:list(TRANSFORM) command. ACTION must be one of the following:
:command:`APPEND <list(TRANSFORM_APPEND)>`, :command:`PREPEND <list(TRANSFORM_APPEND)>`
Append, prepend specified value to each item of the list.
.. code-block:: cmake
$<LIST:TRANSFORM,list,(APPEND|PREPEND),value[,SELECTOR]>
:command:`TOLOWER <list(TRANSFORM_TOLOWER)>`, :command:`TOUPPER <list(TRANSFORM_TOLOWER)>`
Convert each item of the list to lower, upper characters.
.. code-block:: cmake
$<LIST:TRANSFORM,list,(TOLOWER|TOUPPER)[,SELECTOR]>
:command:`STRIP <list(TRANSFORM_STRIP)>`
Remove leading and trailing spaces from each item of the list.
.. code-block:: cmake
$<LIST:TRANSFORM,list,STRIP[,SELECTOR]>
:command:`REPLACE <list(TRANSFORM_REPLACE)>`:
Match the regular expression as many times as possible and substitute
the replacement expression for the match for each item of the list.
.. code-block:: cmake
$<LIST:TRANSFORM,list,REPLACE,regular_expression,replace_expression[,SELECTOR]>
.. versionchanged:: 4.1
The ``^`` anchor now matches only at the beginning of the input
element instead of the beginning of each repeated search.
See policy :policy:`CMP0186`.
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.
.. code-block:: cmake
$<LIST:TRANSFORM,list,ACTION,AT,index[,index...]>
``FOR``
Specify a range with, optionally, an increment used to iterate over the
range.
.. code-block:: cmake
$<LIST:TRANSFORM,list,ACTION,FOR,start,stop[,step]>
``REGEX``
Specify a regular expression.
Only items matching the regular expression will be transformed.
.. code-block:: cmake
$<LIST:TRANSFORM,list,ACTION,REGEX,regular_expression>
.. genex:: $JOIN:list,glue
Joins the list with the content of the glue string inserted between
each item. This is conceptually the same operation as
:cref:$\<LIST:JOIN,list,glue\> <GenEx LIST-JOIN>, but the two have
different behavior with regard to empty items.
:cref:$\<LIST:JOIN,list,glue\> <GenEx LIST-JOIN> preserves all empty items,
whereas $<JOIN:list,glue> drops all empty items from the list.
.. genex:: $<REMOVE_DUPLICATES:list>
.. versionadded:: 3.15
Removes duplicated items in the given list. The relative order of items
is preserved, and if duplicates are encountered, only the first instance is
retained. The result is the same as
:cref:$\<LIST:REMOVE_DUPLICATES,list\> <GenEx LIST-REMOVE_DUPLICATES>.
.. genex:: $FILTER:list,INCLUDE|EXCLUDE,regex
.. versionadded:: 3.15
Includes or removes items from list that match the regular expression
regex. The result is the same as
:cref:$\<LIST:FILTER,list,INCLUDE|EXCLUDE,regex\> <GenEx LIST-FILTER>.
.. _GenEx List Ordering:
List Ordering ^^^^^^^^^^^^^
.. genex:: $LIST:REVERSE,list
.. versionadded:: 3.27
The list with the items in reverse order.
.. genex:: $LIST:SORT,list[,(COMPARE:option|CASE:option|ORDER:option)]...
.. versionadded:: 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.
.. code-block:: cmake
$<LIST:SORT,list,CASE:SENSITIVE,COMPARE:STRING,ORDER:DESCENDING>
Most of the expressions in this section are closely associated with the
:command:cmake_path command, providing the same capabilities, but in
the form of a generator expression.
For all generator expressions in this section, paths are expected to be in
cmake-style format. The :cref:$\<PATH:CMAKE_PATH\> <GenEx PATH-CMAKE_PATH>
generator expression can be used to convert a native path to a cmake-style
one.
.. _GenEx Path Comparisons:
Path Comparisons ^^^^^^^^^^^^^^^^
.. genex:: $<PATH_EQUAL:path1,path2>
.. versionadded:: 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 :ref:cmake_path(COMPARE) <Path Comparison> for more details.
.. _GenEx Path Queries:
Path Queries ^^^^^^^^^^^^
These expressions provide the generation-time capabilities equivalent to the
:ref:Query <Path Query> options of the :command:cmake_path command.
All paths are expected to be in cmake-style format.
.. genex:: $PATH:HAS_*,path
.. versionadded:: 3.24
The following operations return 1 if the particular path component is
present, 0 otherwise. See :ref:Path Structure And Terminology for the
meaning of each path component.
.. code-block:: cmake
$<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 :ref:filename <FILENAME_DEF>.
.. genex:: $PATH:IS_ABSOLUTE,path
.. versionadded:: 3.24
Returns 1 if the path is absolute according to
:command:cmake_path(IS_ABSOLUTE), 0 otherwise.
.. genex:: $PATH:IS_RELATIVE,path
.. versionadded:: 3.24
Returns 1 if the path is relative according to
:command:cmake_path(IS_RELATIVE), 0 otherwise.
.. genex:: $PATH:IS_PREFIX[,NORMALIZE],path,input
.. versionadded:: 3.24
Returns 1 if path is the prefix of input, 0 otherwise.
When the NORMALIZE option is specified, path and input are
:ref:normalized <Normalization> before the check.
.. _GenEx Path Decomposition:
Path Decomposition ^^^^^^^^^^^^^^^^^^
These expressions provide the generation-time capabilities equivalent to the
:ref:Decomposition <Path Decomposition> options of the :command:cmake_path
command. All paths are expected to be in cmake-style format.
.. genex:: $PATH:GET_*,...
.. versionadded:: 3.24
The following operations retrieve a different component or group of
components from a path. See :ref:Path Structure And Terminology for the
meaning of each path component.
.. versionchanged:: 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.
.. code-block:: cmake
$<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.
.. _GenEx Path Transformations:
Path Transformations ^^^^^^^^^^^^^^^^^^^^
These expressions provide the generation-time capabilities equivalent to the
:ref:Modification <Path Modification> and :ref:Generation <Path Generation>
options of the :command:cmake_path command. All paths are expected to be
in cmake-style format.
.. versionchanged:: 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.
.. _GenEx PATH-CMAKE_PATH:
.. genex:: $PATH:CMAKE_PATH[,NORMALIZE],path...
.. versionadded:: 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 :ref:normalized <Normalization> after the conversion.
.. genex:: $PATH:NATIVE_PATH[,NORMALIZE],path...
.. versionadded:: 4.0
Returns path converted into a native format with platform-specific
slashes (\ on Windows hosts and / elsewhere).
When the NORMALIZE option is specified, the path is :ref:normalized <Normalization> before the conversion.
.. genex:: $PATH:APPEND,path...,input,...
.. versionadded:: 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 :command:cmake_path(APPEND) for more details.
.. genex:: $PATH:REMOVE_FILENAME,path...
.. versionadded:: 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 :command:cmake_path(REMOVE_FILENAME) for more details.
.. genex:: $PATH:REPLACE_FILENAME,path...,input
.. versionadded:: 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 :command:cmake_path(REPLACE_FILENAME) for more details.
.. genex:: $PATH:REMOVE_EXTENSION[,LAST_ONLY],path...
.. versionadded:: 3.24
Returns path with the :ref:extension <EXTENSION_DEF> removed, if any.
See :command:cmake_path(REMOVE_EXTENSION) for more details.
.. genex:: $PATH:REPLACE_EXTENSION[,LAST_ONLY],path...,input
.. versionadded:: 3.24
Returns path with the :ref:extension <EXTENSION_DEF> replaced by
input, if any.
See :command:cmake_path(REPLACE_EXTENSION) for more details.
.. genex:: $PATH:NORMAL_PATH,path...
.. versionadded:: 3.24
Returns path normalized according to the steps described in
:ref:Normalization.
.. genex:: $PATH:RELATIVE_PATH,path...,base_directory
.. versionadded:: 3.24
Returns path, modified to make it relative to the base_directory
argument.
See :command:cmake_path(RELATIVE_PATH) for more details.
.. genex:: $PATH:ABSOLUTE_PATH[,NORMALIZE],path...,base_directory
.. versionadded:: 3.24
Returns path as absolute. If path is a relative path
($<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
:ref:normalized <Normalization> after the path computation.
See :command:cmake_path(ABSOLUTE_PATH) for more details.
Shell Paths ^^^^^^^^^^^
.. genex:: $<SHELL_PATH:...>
.. versionadded:: 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.
.. versionadded:: 3.14
The ... may be a :ref:semicolon-separated list <CMake Language Lists>
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.
.. genex:: $<CONFIG>
Configuration name. Use this instead of the deprecated :genex:CONFIGURATION
generator expression.
.. genex:: $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
:prop_tgt:MAP_IMPORTED_CONFIG_<CONFIG> is also considered by this
expression when it is evaluated on a property of an :prop_tgt:IMPORTED
target.
.. versionchanged:: 3.19
Multiple configurations can be specified for cfgs.
CMake 3.18 and earlier only accepted a single configuration.
.. genex:: $<OUTPUT_CONFIG:...>
.. versionadded:: 3.20
Only valid in :command:add_custom_command and :command:add_custom_target
as the outer-most generator expression in an argument.
With the :generator: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.
.. genex:: $<COMMAND_CONFIG:...>
.. versionadded:: 3.20
Only valid in :command:add_custom_command and :command:add_custom_target
as the outer-most generator expression in an argument.
With the :generator: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.
Platform ^^^^^^^^
.. genex:: $<PLATFORM_ID>
The current system's CMake platform id.
See also the :variable:CMAKE_SYSTEM_NAME variable.
.. genex:: $<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 :variable:CMAKE_SYSTEM_NAME variable.
Compiler Version ^^^^^^^^^^^^^^^^
See also the :variable:CMAKE_<LANG>_COMPILER_VERSION variable, which is
closely related to the expressions in this sub-section.
.. genex:: $<C_COMPILER_VERSION>
The version of the C compiler used.
.. genex:: $<C_COMPILER_VERSION:version>
1 if the version of the C compiler matches version, otherwise 0.
.. genex:: $<CXX_COMPILER_VERSION>
The version of the CXX compiler used.
.. genex:: $<CXX_COMPILER_VERSION:version>
1 if the version of the C++ compiler matches version, otherwise 0.
.. genex:: $<CUDA_COMPILER_VERSION>
.. versionadded:: 3.15
The version of the CUDA compiler used.
.. genex:: $<CUDA_COMPILER_VERSION:version>
.. versionadded:: 3.15
1 if the version of the C++ compiler matches version, otherwise 0.
.. genex:: $<OBJC_COMPILER_VERSION>
.. versionadded:: 3.16
The version of the Objective-C compiler used.
.. genex:: $<OBJC_COMPILER_VERSION:version>
.. versionadded:: 3.16
1 if the version of the Objective-C compiler matches version, otherwise 0.
.. genex:: $<OBJCXX_COMPILER_VERSION>
.. versionadded:: 3.16
The version of the Objective-C++ compiler used.
.. genex:: $<OBJCXX_COMPILER_VERSION:version>
.. versionadded:: 3.16
1 if the version of the Objective-C++ compiler matches version, otherwise 0.
.. genex:: $<Fortran_COMPILER_VERSION>
The version of the Fortran compiler used.
.. genex:: $<Fortran_COMPILER_VERSION:version>
1 if the version of the Fortran compiler matches version, otherwise 0.
.. genex:: $<HIP_COMPILER_VERSION>
.. versionadded:: 3.21
The version of the HIP compiler used.
.. genex:: $<HIP_COMPILER_VERSION:version>
.. versionadded:: 3.21
1 if the version of the HIP compiler matches version, otherwise 0.
.. genex:: $<ISPC_COMPILER_VERSION>
.. versionadded:: 3.19
The version of the ISPC compiler used.
.. genex:: $<ISPC_COMPILER_VERSION:version>
.. versionadded:: 3.19
1 if the version of the ISPC compiler matches version, otherwise 0.
Compiler Language, ID, and Frontend-Variant ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
See also the :variable:CMAKE_<LANG>_COMPILER_ID and
:variable:CMAKE_<LANG>_COMPILER_FRONTEND_VARIANT variables, which are closely
related to most of the expressions in this sub-section.
.. genex:: $<C_COMPILER_ID>
CMake's compiler id of the C compiler used.
.. genex:: $<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.
.. versionchanged:: 3.15
Multiple compiler_ids can be specified.
CMake 3.14 and earlier only accepted a single compiler ID.
.. genex:: $<CXX_COMPILER_ID>
CMake's compiler id of the C++ compiler used.
.. genex:: $<CXX_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.
.. versionchanged:: 3.15
Multiple compiler_ids can be specified.
CMake 3.14 and earlier only accepted a single compiler ID.
.. genex:: $<CUDA_COMPILER_ID>
.. versionadded:: 3.15
CMake's compiler id of the CUDA compiler used.
.. genex:: $<CUDA_COMPILER_ID:compiler_ids>
.. versionadded:: 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.
.. genex:: $<OBJC_COMPILER_ID>
.. versionadded:: 3.16
CMake's compiler id of the Objective-C compiler used.
.. genex:: $<OBJC_COMPILER_ID:compiler_ids>
.. versionadded:: 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.
.. genex:: $<OBJCXX_COMPILER_ID>
.. versionadded:: 3.16
CMake's compiler id of the Objective-C++ compiler used.
.. genex:: $<OBJCXX_COMPILER_ID:compiler_ids>
.. versionadded:: 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.
.. genex:: $<Fortran_COMPILER_ID>
CMake's compiler id of the Fortran compiler used.
.. genex:: $<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.
.. versionchanged:: 3.15
Multiple compiler_ids can be specified.
CMake 3.14 and earlier only accepted a single compiler ID.
.. genex:: $<HIP_COMPILER_ID>
.. versionadded:: 3.21
CMake's compiler id of the HIP compiler used.
.. genex:: $<HIP_COMPILER_ID:compiler_ids>
.. versionadded:: 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.
.. genex:: $<ISPC_COMPILER_ID>
.. versionadded:: 3.19
CMake's compiler id of the ISPC compiler used.
.. genex:: $<ISPC_COMPILER_ID:compiler_ids>
.. versionadded:: 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.
.. genex:: $<C_COMPILER_FRONTEND_VARIANT>
.. versionadded:: 3.30
CMake's compiler frontend variant of the C compiler used.
.. genex:: $<C_COMPILER_FRONTEND_VARIANT:compiler_ids>
.. versionadded:: 3.30
where compiler_ids is a comma-separated list.
1 if CMake's compiler frontend variant of the C compiler matches any one
of the entries in compiler_ids, otherwise 0.
.. genex:: $<CXX_COMPILER_FRONTEND_VARIANT>
.. versionadded:: 3.30
CMake's compiler frontend variant of the C++ compiler used.
.. genex:: $<CXX_COMPILER_FRONTEND_VARIANT:compiler_ids>
.. versionadded:: 3.30
where compiler_ids is a comma-separated list.
1 if CMake's compiler frontend variant of the C++ compiler matches any one
of the entries in compiler_ids, otherwise 0.
.. genex:: $<CUDA_COMPILER_FRONTEND_VARIANT>
.. versionadded:: 3.30
CMake's compiler id of the CUDA compiler used.
.. genex:: $<CUDA_COMPILER_FRONTEND_VARIANT:compiler_ids>
.. versionadded:: 3.30
where compiler_ids is a comma-separated list.
1 if CMake's compiler frontend variant of the CUDA compiler matches any one
of the entries in compiler_ids, otherwise 0.
.. genex:: $<OBJC_COMPILER_FRONTEND_VARIANT>
.. versionadded:: 3.30
CMake's compiler frontend variant of the Objective-C compiler used.
.. genex:: $<OBJC_COMPILER_FRONTEND_VARIANT:compiler_ids>
.. versionadded:: 3.30
where compiler_ids is a comma-separated list.
1 if CMake's compiler frontend variant of the Objective-C compiler matches any one
of the entries in compiler_ids, otherwise 0.
.. genex:: $<OBJCXX_COMPILER_FRONTEND_VARIANT>
.. versionadded:: 3.30
CMake's compiler frontend variant of the Objective-C++ compiler used.
.. genex:: $<OBJCXX_COMPILER_FRONTEND_VARIANT:compiler_ids>
.. versionadded:: 3.30
where compiler_ids is a comma-separated list.
1 if CMake's compiler frontend variant of the Objective-C++ compiler matches any one
of the entries in compiler_ids, otherwise 0.
.. genex:: $<Fortran_COMPILER_FRONTEND_VARIANT>
.. versionadded:: 3.30
CMake's compiler id of the Fortran compiler used.
.. genex:: $<Fortran_COMPILER_FRONTEND_VARIANT:compiler_ids>
.. versionadded:: 3.30
where compiler_ids is a comma-separated list.
1 if CMake's compiler frontend variant of the Fortran compiler matches any one
of the entries in compiler_ids, otherwise 0.
.. genex:: $<HIP_COMPILER_FRONTEND_VARIANT>
.. versionadded:: 3.30
CMake's compiler id of the HIP compiler used.
.. genex:: $<HIP_COMPILER_FRONTEND_VARIANT:compiler_ids>
.. versionadded:: 3.30
where compiler_ids is a comma-separated list.
1 if CMake's compiler frontend variant of the HIP compiler matches any one
of the entries in compiler_ids, otherwise 0.
.. genex:: $<ISPC_COMPILER_FRONTEND_VARIANT>
.. versionadded:: 3.30
CMake's compiler id of the ISPC compiler used.
.. genex:: $<ISPC_COMPILER_FRONTEND_VARIANT:compiler_ids>
.. versionadded:: 3.30
where compiler_ids is a comma-separated list.
1 if CMake's compiler frontend variant of the ISPC compiler matches any one
of the entries in compiler_ids, otherwise 0.
.. genex:: $<COMPILE_LANGUAGE>
.. versionadded:: 3.3
The compile language of source files when evaluating compile options.
See the related boolean expression
:genex:$<COMPILE_LANGUAGE:languages> <COMPILE_LANGUAGE:languages>
for notes about the portability of this generator expression.
.. genex:: $<COMPILE_LANGUAGE:languages> :target: COMPILE_LANGUAGE:languages
.. versionadded:: 3.3
.. versionchanged:: 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:
.. code-block:: cmake
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 :ref:Visual Studio Generators and :generator:Xcode there
is no way to represent target-wide compile definitions or include directories
separately for C and CXX languages.
Also, with :ref: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:
.. code-block:: cmake
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)
.. genex:: $<COMPILE_LANG_AND_ID:language,compiler_ids>
.. versionadded:: 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:
.. code-block:: cmake
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:
.. code-block:: cmake
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 ^^^^^^^^^^^^^^^^
.. genex:: $<COMPILE_FEATURES:features>
.. versionadded:: 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 :prop_tgt:C_STANDARD or :prop_tgt:CXX_STANDARD
for the 'head' target, an error is reported. See the
:manual:cmake-compile-features(7) manual for information on
compile features and a list of supported compilers.
Compile Context ^^^^^^^^^^^^^^^
.. genex:: $<COMPILE_ONLY:...>
.. versionadded:: 3.27
Content of ..., when collecting
:ref:transitive compile properties <Transitive Compile Properties>,
otherwise it is the empty string. This is intended for use in an
:prop_tgt:INTERFACE_LINK_LIBRARIES and :prop_tgt:LINK_LIBRARIES target
properties, typically populated via the :command: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 :policy:CMP0099
to be set to NEW.
Link Language and ID ^^^^^^^^^^^^^^^^^^^^
.. genex:: $<LINK_LANGUAGE>
.. versionadded:: 3.18
The link language of the target when evaluating link options.
See :ref:the related boolean expression <Boolean LINK_LANGUAGE Generator 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.
.. _Boolean LINK_LANGUAGE Generator Expression:
.. genex:: $<LINK_LANGUAGE:languages>
.. versionadded:: 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:
.. code-block:: cmake
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.
.. _Constraints LINK_LANGUAGE Generator Expression:
.. 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:
.. code-block:: cmake
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.
.. genex:: $<LINK_LANG_AND_ID:language,compiler_ids>
.. versionadded:: 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:
.. code-block:: cmake
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 :ref:the note related to <Constraints LINK_LANGUAGE Generator Expression>
$<LINK_LANGUAGE:language> for constraints about the usage of this
generator expression.
Link Features ^^^^^^^^^^^^^
.. genex:: $<LINK_LIBRARY:feature,library-list>
.. versionadded:: 3.24
Specify a set of libraries to link to a target, along with a feature
which provides details about how they should be linked. For example:
.. code-block:: cmake
add_library(lib1 STATIC ...)
add_library(lib2 ...)
target_link_libraries(lib2 PRIVATE "$<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:
.. include:: ../variable/include/LINK_LIBRARY_PREDEFINED_FEATURES.rst
Built-in and custom library features are defined in terms of the following variables:
CMAKE_<LANG>_LINK_LIBRARY_USING_<FEATURE>_SUPPORTEDCMAKE_<LANG>_LINK_LIBRARY_USING_<FEATURE>CMAKE_LINK_LIBRARY_USING_<FEATURE>_SUPPORTEDCMAKE_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:
CMAKE_<LANG>_LINK_LIBRARY_USING_<FEATURE>_SUPPORTED variable
is true, the feature must be defined by the corresponding
:variable:CMAKE_<LANG>_LINK_LIBRARY_USING_<FEATURE> variable.feature is supported, then the
:variable:CMAKE_LINK_LIBRARY_USING_<FEATURE>_SUPPORTED variable must be
true and the feature must be defined by the corresponding
:variable: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 :ref:OBJECT <Object Libraries>
or :ref:INTERFACE <Interface Libraries> 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
:prop_tgt:LINK_LIBRARIES, :prop_tgt:INTERFACE_LINK_LIBRARIES, and
:prop_tgt:INTERFACE_LINK_LIBRARIES_DIRECT target properties, and be
specified in :command:target_link_libraries and :command:link_libraries
commands.
If a $<LINK_LIBRARY:...> generator expression appears in the
:prop_tgt:INTERFACE_LINK_LIBRARIES property of a target, it will be
included in the imported target generated by a :command:install(EXPORT)
command. It is the responsibility of the environment consuming this
import to define the link feature used by this expression.
Each target or library involved in the link step must have at most only one kind of library feature. The absence of a feature is also incompatible with all other features. For example:
.. code-block:: cmake
add_library(lib1 ...) add_library(lib2 ...) add_library(lib3 ...)
target_link_libraries(lib2 PUBLIC "$<LINK_LIBRARY:feature1,lib1>")
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 :prop_tgt:LINK_LIBRARY_OVERRIDE and
:prop_tgt: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 :genex:LINK_GROUP
generator expression instead.
.. genex:: $<LINK_GROUP:feature,library-list>
.. versionadded:: 3.24
Specify a group of libraries to link to a target, along with a feature
which defines how that group should be linked. For example:
.. code-block:: cmake
add_library(lib1 STATIC ...)
add_library(lib2 ...)
target_link_libraries(lib2 PRIVATE "$<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:
.. include:: ../variable/include/LINK_GROUP_PREDEFINED_FEATURES.rst
Built-in and custom group features are defined in terms of the following variables:
CMAKE_<LANG>_LINK_GROUP_USING_<FEATURE>_SUPPORTEDCMAKE_<LANG>_LINK_GROUP_USING_<FEATURE>CMAKE_LINK_GROUP_USING_<FEATURE>_SUPPORTEDCMAKE_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:
CMAKE_<LANG>_LINK_GROUP_USING_<FEATURE>_SUPPORTED variable
is true, the feature must be defined by the corresponding
:variable:CMAKE_<LANG>_LINK_GROUP_USING_<FEATURE> variable.feature is supported, then the
:variable:CMAKE_LINK_GROUP_USING_<FEATURE>_SUPPORTED variable must be
true and the feature must be defined by the corresponding
:variable:CMAKE_LINK_GROUP_USING_<FEATURE> variable.The LINK_GROUP generator expression is compatible with the
:genex:LINK_LIBRARY generator expression. The libraries involved in a
group can be specified using the :genex: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.
.. code-block:: cmake
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 "$<LINK_GROUP:feature2,lib1,lib3>")
# An error will be raised here because both lib1 and lib3 are part of two
# groups with different features.
When a target or an external library is involved in the link step as part of a group and also as not part of any group, any occurrence of the non-group link item will be replaced by the groups it belongs to.
.. code-block:: cmake
add_library(lib1 ...)
add_library(lib2 ...)
add_library(lib3 ...)
add_library(lib4 ...)
target_link_libraries(lib3 PUBLIC lib1)
target_link_libraries(lib4 PRIVATE lib3 "$<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:
.. code-block:: cmake
target_link_libraries(lib3 PUBLIC "$<LINK_GROUP:feature1,lib1,lib2>")
Be aware that the precedence of the group over the non-group link item can result in circular dependencies between groups. If this occurs, a fatal error is raised because circular dependencies are not allowed for groups.
.. code-block:: cmake
add_library(lib1A ...)
add_library(lib1B ...)
add_library(lib2A ...)
add_library(lib2B ...)
add_library(lib3 ...)
# Non-group linking relationships, these are non-circular so far
target_link_libraries(lib1A PUBLIC lib2A)
target_link_libraries(lib2B PUBLIC lib1B)
# The addition of these groups creates circular dependencies
target_link_libraries(lib3 PRIVATE
"$<LINK_GROUP:feat,lib1A,lib1B>"
"$<LINK_GROUP:feat,lib2A,lib2B>"
)
Because of the groups defined for lib3, the linking relationships for
lib1A and lib2B effectively get expanded to the equivalent of:
.. code-block:: cmake
target_link_libraries(lib1A PUBLIC "$<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 :ref:OBJECT <Object Libraries>
or :ref:INTERFACE <Interface Libraries> 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
:prop_tgt:LINK_LIBRARIES, :prop_tgt:INTERFACE_LINK_LIBRARIES,and
:prop_tgt:INTERFACE_LINK_LIBRARIES_DIRECT target properties, and be
specified in :command:target_link_libraries and :command:link_libraries
commands.
If a $<LINK_GROUP:...> generator expression appears in the
:prop_tgt:INTERFACE_LINK_LIBRARIES property of a target, it will be
included in the imported target generated by a :command:install(EXPORT)
command. It is the responsibility of the environment consuming this
import to define the link feature used by this expression.
Link Context ^^^^^^^^^^^^
.. genex:: $<LINK_ONLY:...>
.. versionadded:: 3.1
Content of ..., except while collecting usage requirements from
:ref:transitive compile properties <Transitive Compile Properties>,
in which case it is the empty string. This is intended for use in an
:prop_tgt:INTERFACE_LINK_LIBRARIES target property, typically populated
via the :command:target_link_libraries command, to specify private link
dependencies without other usage requirements such as include directories or
compile options.
.. versionadded:: 3.24
LINK_ONLY may also be used in a :prop_tgt:LINK_LIBRARIES target
property. See policy :policy:CMP0131.
.. genex:: $<DEVICE_LINK:list>
.. versionadded:: 3.18
Returns the list if it is the device link step, an empty list otherwise.
The device link step is controlled by :prop_tgt:CUDA_SEPARABLE_COMPILATION
and :prop_tgt:CUDA_RESOLVE_DEVICE_SYMBOLS properties and
policy :policy:CMP0105. This expression can only be used to specify link
options.
.. genex:: $<HOST_LINK:list>
.. versionadded:: 3.18
Returns the list if it is the normal link step, an empty list otherwise.
This expression is mainly useful when a device link step is also involved
(see :genex:$<DEVICE_LINK:list> generator expression). This expression can
only be used to specify link options.
Linker ID and Frontend-Variant ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
See also the :variable:CMAKE_<LANG>_COMPILER_LINKER_ID and
:variable:CMAKE_<LANG>_COMPILER_LINKER_FRONTEND_VARIANT variables, which are
closely related to most of the expressions in this sub-section.
.. genex:: $<C_COMPILER_LINKER_ID>
.. versionadded:: 4.2
CMake's linker id of the C linker used.
.. genex:: $<C_COMPILER_LINKER_ID:linker_ids>
.. versionadded:: 4.2
where linker_ids is a comma-separated list.
1 if CMake's linker id of the C linker matches any one
of the entries in linker_ids, otherwise 0.
.. genex:: $<CXX_COMPILER_LINKER_ID>
.. versionadded:: 4.2
CMake's linker id of the C++ linker used.
.. genex:: $<CXX_COMPILER_LINKER_ID:linker_ids>
.. versionadded:: 4.2
where linker_ids is a comma-separated list.
1 if CMake's linker id of the C++ linker matches any one
of the entries in linker_ids, otherwise 0.
.. genex:: $<CUDA_COMPILER_LINKER_ID>
.. versionadded:: 4.2
CMake's linker id of the CUDA linker used.
.. genex:: $<CUDA_COMPILER_LINKER_ID:linker_ids>
.. versionadded:: 4.2
where linker_ids is a comma-separated list.
1 if CMake's linker id of the CUDA linker matches any one
of the entries in linker_ids, otherwise 0.
.. genex:: $<OBJC_COMPILER_LINKER_ID>
.. versionadded:: 4.2
CMake's linker id of the Objective-C linker used.
.. genex:: $<OBJC_COMPILER_LINKER_ID:linker_ids>
.. versionadded:: 4.2
where linker_ids is a comma-separated list.
1 if CMake's linker id of the Objective-C linker matches any one
of the entries in linker_ids, otherwise 0.
.. genex:: $<OBJCXX_COMPILER_LINKER_ID>
.. versionadded:: 4.2
CMake's linker id of the Objective-C++ linker used.
.. genex:: $<OBJCXX_COMPILER_LINKER_ID:linker_ids>
.. versionadded:: 4.2
where linker_ids is a comma-separated list.
1 if CMake's linker id of the Objective-C++ linker matches any one
of the entries in linker_ids, otherwise 0.
.. genex:: $<Fortran_COMPILER_LINKER_ID>
.. versionadded:: 4.2
CMake's linker id of the Fortran linker used.
.. genex:: $<Fortran_COMPILER_LINKER_ID:linker_ids>
.. versionadded:: 4.2
where linker_ids is a comma-separated list.
1 if CMake's linker id of the Fortran linker matches any one
of the entries in linker_ids, otherwise 0.
.. genex:: $<HIP_COMPILER_LINKER_ID>
.. versionadded:: 4.2
CMake's linker id of the HIP linker used.
.. genex:: $<HIP_COMPILER_LINKER_ID:linker_ids>
.. versionadded:: 4.2
where linker_ids is a comma-separated list.
1 if CMake's linker id of the HIP linker matches any one
of the entries in linker_ids, otherwise 0.
.. genex:: $<C_COMPILER_LINKER_FRONTEND_VARIANT>
.. versionadded:: 4.2
CMake's linker frontend variant of the C linker used.
.. genex:: $<C_COMPILER_LINKER_FRONTEND_VARIANT:variant_ids>
.. versionadded:: 4.2
where variant_ids is a comma-separated list.
1 if CMake's linker frontend variant of the C linker matches any one
of the entries in variant_ids, otherwise 0.
.. genex:: $<CXX_COMPILER_LINKER_FRONTEND_VARIANT>
.. versionadded:: 4.2
CMake's linker frontend variant of the C++ linker used.
.. genex:: $<CXX_COMPILER_LINKER_FRONTEND_VARIANT:variant_ids>
.. versionadded:: 4.2
where variant_ids is a comma-separated list.
1 if CMake's linker frontend variant of the C++ linker matches any one
of the entries in variant_ids, otherwise 0.
.. genex:: $<CUDA_COMPILER_LINKER_FRONTEND_VARIANT>
.. versionadded:: 4.2
CMake's linker frontend variant of the CUDA linker used.
.. genex:: $<CUDA_COMPILER_LINKER_FRONTEND_VARIANT:variant_ids>
.. versionadded:: 4.2
where variant_ids is a comma-separated list.
1 if CMake's linker frontend variant of the CUDA linker matches any one
of the entries in variant_ids, otherwise 0.
.. genex:: $<OBJC_COMPILER_LINKER_FRONTEND_VARIANT>
.. versionadded:: 4.2
CMake's linker frontend variant of the Objective-C linker used.
.. genex:: $<OBJC_COMPILER_LINKER_FRONTEND_VARIANT:variant_ids>
.. versionadded:: 4.2
where variant_ids is a comma-separated list.
1 if CMake's linker frontend variant of the Objective-C linker matches
any one of the entries in variant_ids, otherwise 0.
.. genex:: $<OBJCXX_COMPILER_LINKER_FRONTEND_VARIANT>
.. versionadded:: 4.2
CMake's linker frontend variant of the Objective-C++ linker used.
.. genex:: $<OBJCXX_COMPILER_LINKER_FRONTEND_VARIANT:variant_ids>
.. versionadded:: 4.2
where variant_ids is a comma-separated list.
1 if CMake's linker frontend variant of the Objective-C++ linker matches
any one of the entries in variant_ids, otherwise 0.
.. genex:: $<Fortran_COMPILER_LINKER_FRONTEND_VARIANT>
.. versionadded:: 4.2
CMake's linker frontend variant of the Fortran linker used.
.. genex:: $<Fortran_COMPILER_LINKER_FRONTEND_VARIANT:variant_ids>
.. versionadded:: 4.2
where variant_ids is a comma-separated list.
1 if CMake's linker frontend variant of the Fortran linker matches
any one of the entries in variant_ids, otherwise 0.
.. genex:: $<HIP_COMPILER_LINKER_FRONTEND_VARIANT>
.. versionadded:: 4.2
CMake's linker frontend variant of the HIP linker used.
.. genex:: $<HIP_COMPILER_LINKER_FRONTEND_VARIANT:variant_ids>
.. versionadded:: 4.2
where variant_ids is a comma-separated list.
1 if CMake's linker frontend variant of the HIP linker matches
any one of the entries in variant_ids, otherwise 0.
.. _Source-Dependent Expressions:
The source file, as specified in the following expressions, can be nonexistent on the file system (i.e. generated file) but must be known from CMake. A source file becomes known from CMake if it is part of some target (library or executable) or when a source file property is defined. Moreover, this information is specific to the directory where the declaration occurred.
For example, these generator expressions enable to offer a uniform behavior,
for the :command:add_custom_command and :command:add_custom_target
commands, regarding the source properties:
.. code-block:: cmake
function(custom_add_library target) unset(sources) foreach(source IN LISTS ARGN) add_custom_command( OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${source}.bin COMMAND my-compiler -o ${CMAKE_CURRENT_BINARY_DIR}/${source}.bin "$<$<SOURCE_EXISTS:${source}>:$<SOURCE_PROPERTY:${source},COMPILE_OPTIONS>>" ${source}) list(APPEND sources ${CMAKE_CURRENT_BINARY_DIR}/${source}.bin) endforeach() add_custom_target(${target} DEPENDS ${sources}) endfunction()
custom_add_library(my-lib file1.x file2.x file3.x) set_property(SOURCE file1.x PROPERTY COMPILE_OPTIONS -X) set_property(SOURCE file2.x PROPERTY COMPILE_OPTIONS -Y)
Source Meta-Data ^^^^^^^^^^^^^^^^
These expressions look up information about a source file.
.. genex:: $<SOURCE_EXISTS:src[,(DIRECTORY:dir|TARGET_DIRECTORY:tgt)]>
.. versionadded:: 4.3
1 if src exists as a CMake source file, else 0. By default, the
source file is searched in the scope of the current source directory or the
directory of the consuming target.
Directory scope can be overridden with one of the following sub-options:
DIRECTORY:dir
The source file will be searched in the dir directory's scope.
CMake must know about the directory, either by having added it through a
call to :command:add_subdirectory or dir being the top level
directory. Relative paths are treated as relative to the current source
directory.
TARGET_DIRECTORY:target
The source file will be searched in the directory scope in which
target was created (target must therefore exist).
Source Properties ^^^^^^^^^^^^^^^^^
These expressions look up the values of
:ref:source file properties <Source File Properties>.
.. genex:: $<SOURCE_PROPERTY:src[,(DIRECTORY:dir|TARGET_DIRECTORY:target)],prop>
.. versionadded:: 4.3
Value of the property prop on the source file src, or empty if
the property is not set. An error will be raised if the source file is not
known by CMake. By default, the source file's property will be read from the
current source directory's scope or the directory of the consuming target.
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 know about the directory, either by having added it through a
call to :command:add_subdirectory or dir being the top level
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 exist).
.. _FileSet-Dependent Expressions:
FileSet Meta-Data ^^^^^^^^^^^^^^^^^
These expressions look up information about a file set.
.. genex:: $<FILE_SET_EXISTS:fileset,TARGET:target>
.. versionadded:: 4.3
1 if the fileset exists as a CMake file set attached to the
target, else 0.
The possible sub-options are:
TARGET:target
The target on which the file set depends.
FileSet Properties ^^^^^^^^^^^^^^^^^^
These expressions look up the values of file set properties.
.. genex:: $<FILE_SET_PROPERTY:fileset,TARGET:target,prop>
.. versionadded:: 4.3
Value of the property prop on the file set fileset, or empty if
the property is not set. An error will be raised if the file set is not
known by CMake.
The possible sub-options are:
TARGET:target
The target on which the file set depends.
.. _Target-Dependent Expressions:
Target Meta-Data ^^^^^^^^^^^^^^^^
These expressions look up information about a target.
.. genex:: $<TARGET_EXISTS:tgt>
.. versionadded:: 3.12
1 if tgt exists as a CMake target, else 0.
.. genex:: $<TARGET_NAME_IF_EXISTS:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_NAME:tgt>
The target name tgt as written. This marks tgt as being the name
of a target inside a larger expression, which is required if exporting
targets to multiple dependent export sets. The tgt text must be a
literal name of a target; it may not contain generator expressions.
The target does not have to exist.
.. genex:: $<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 Properties ^^^^^^^^^^^^^^^^^
These expressions look up the values of
:ref:target properties <Target Properties>.
.. genex:: $<TARGET_PROPERTY:tgt,prop>
Value of the property prop on the target tgt, or empty if
the property is not set.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. versionchanged:: 3.26
When encountered during evaluation of :ref:Target 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.
.. genex:: $<TARGET_PROPERTY:prop> :target: TARGET_PROPERTY:prop
Value of the property prop on the target for which the expression
is being evaluated, or empty if the property is not set.
Note that for generator expressions in :ref:Target Usage Requirements
this is the consuming target rather than the target specifying the
requirement.
The expressions have special evaluation rules for some properties:
:ref:Target Build Specification Properties <Target Build Specification>
These evaluate as a :ref:semicolon-separated list <CMake Language Lists>
representing the union of the value on the target itself with the values
of the corresponding :ref:Target Usage Requirements on targets named by
the target's :prop_tgt:LINK_LIBRARIES:
For :ref:Target Compile Properties, evaluation of corresponding usage
requirements is transitive over the closure of the linked targets'
:prop_tgt:INTERFACE_LINK_LIBRARIES excluding entries guarded by the
:genex:LINK_ONLY generator expression.
For :ref:Target Link Properties, evaluation of corresponding usage
requirements is transitive over the closure of the linked targets'
:prop_tgt:INTERFACE_LINK_LIBRARIES including entries guarded by the
:genex:LINK_ONLY generator expression. See policy :policy:CMP0166.
.. versionchanged:: 4.1
Evaluation of :prop_tgt:`LINK_LIBRARIES` itself is now transitive.
See policy :policy:`CMP0189`.
:ref:Target Usage Requirement Properties <Target Usage Requirements>
These evaluate as a :ref:semicolon-separated list <CMake Language Lists>
representing the union of the value on the target itself with the values
of the same properties on targets named by the target's
:prop_tgt:INTERFACE_LINK_LIBRARIES:
For :ref:Transitive Compile Properties, evaluation is transitive over
the closure of the target's :prop_tgt:INTERFACE_LINK_LIBRARIES
excluding entries guarded by the :genex:LINK_ONLY generator expression.
For :ref:Transitive Link Properties, evaluation is transitive over
the closure of the target's :prop_tgt:INTERFACE_LINK_LIBRARIES
including entries guarded by the :genex:LINK_ONLY generator expression.
See policy :policy:CMP0166.
.. versionchanged:: 4.1
Evaluation of :prop_tgt:`INTERFACE_LINK_LIBRARIES` itself is now
transitive. See policy :policy:`CMP0189`.
:ref:Custom Transitive Properties
.. versionadded:: 3.30
These are processed during evaluation as follows:
Evaluation of :genex:$<TARGET_PROPERTY:tgt,PROP> for some property
PROP, named without an INTERFACE_ prefix,
checks the :prop_tgt:TRANSITIVE_COMPILE_PROPERTIES
and :prop_tgt:TRANSITIVE_LINK_PROPERTIES properties on target tgt,
on targets named by its :prop_tgt:LINK_LIBRARIES, and on the
transitive closure of targets named by the linked targets'
:prop_tgt:INTERFACE_LINK_LIBRARIES.
If PROP is listed by one of those properties, then it evaluates as
a :ref:semicolon-separated list <CMake Language Lists> representing
the union of the value on the target itself with the values of the
corresponding INTERFACE_PROP on targets named by the target's
:prop_tgt:LINK_LIBRARIES:
If PROP is named by :prop_tgt:TRANSITIVE_COMPILE_PROPERTIES,
evaluation of the corresponding INTERFACE_PROP is transitive over
the closure of the linked targets' :prop_tgt:INTERFACE_LINK_LIBRARIES,
excluding entries guarded by the :genex:LINK_ONLY generator expression.
If PROP is named by :prop_tgt:TRANSITIVE_LINK_PROPERTIES,
evaluation of the corresponding INTERFACE_PROP is transitive over
the closure of the linked targets' :prop_tgt:INTERFACE_LINK_LIBRARIES,
including entries guarded by the :genex:LINK_ONLY generator expression.
Evaluation of :genex:$<TARGET_PROPERTY:tgt,INTERFACE_PROP> for some
property INTERFACE_PROP, named with an INTERFACE_ prefix,
checks the :prop_tgt:TRANSITIVE_COMPILE_PROPERTIES
and :prop_tgt:TRANSITIVE_LINK_PROPERTIES properties on target tgt,
and on the transitive closure of targets named by its
:prop_tgt:INTERFACE_LINK_LIBRARIES.
If the corresponding PROP is listed by one of those properties,
then INTERFACE_PROP evaluates as a
:ref:semicolon-separated list <CMake Language Lists> representing the
union of the value on the target itself with the value of the same
property on targets named by the target's
:prop_tgt:INTERFACE_LINK_LIBRARIES:
If PROP is named by :prop_tgt:TRANSITIVE_COMPILE_PROPERTIES,
evaluation of the corresponding INTERFACE_PROP is transitive over
the closure of the target's :prop_tgt:INTERFACE_LINK_LIBRARIES,
excluding entries guarded by the :genex:LINK_ONLY generator expression.
If PROP is named by :prop_tgt:TRANSITIVE_LINK_PROPERTIES,
evaluation of the corresponding INTERFACE_PROP is transitive over
the closure of the target's :prop_tgt:INTERFACE_LINK_LIBRARIES,
including entries guarded by the :genex:LINK_ONLY generator expression.
If a PROP is named by both :prop_tgt:TRANSITIVE_COMPILE_PROPERTIES
and :prop_tgt:TRANSITIVE_LINK_PROPERTIES, the latter takes precedence.
:ref:Compatible Interface Properties
These evaluate as a single value combined from the target itself,
from targets named by the target's :prop_tgt:LINK_LIBRARIES, and
from the transitive closure of the linked targets'
:prop_tgt:INTERFACE_LINK_LIBRARIES. Values of a compatible
interface property from multiple targets combine based on the type
of compatibility required by the COMPATIBLE_INTERFACE_* property
defining it.
Target Artifacts ^^^^^^^^^^^^^^^^
These expressions look up information about artifacts associated with
a given target tgt. Unless otherwise stated, this can be any
runtime artifact, namely:
add_executable..so, .dll but not their .lib import
library) created by :command:add_library.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.
.. genex:: $<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
:command:add_custom_command or :command:add_custom_target.
.. genex:: $<TARGET_FILE_BASE_NAME:tgt[,POSTFIX:(INCLUDE|EXCLUDE)]>
.. versionadded:: 3.15
.. versionadded:: 4.2
The POSTFIX option can be used to control the inclusion or not
of the :prop_tgt:<CONFIG>_POSTFIX target property value as part of the
base name. The default is POSTFIX:INCLUDE.
Base name of tgt, i.e. $<TARGET_FILE_NAME:tgt> without prefix and
suffix and, optionally, postfix.
For example, if the tgt filename is libbase_postfix.so, the base name
is:
* ``base_postfix`` for ``$<TARGET_FILE_BASE_NAME:tgt>`` or
``$<TARGET_FILE_BASE_NAME:tgt,POSTFIX:INCLUDE>``.
* ``base`` for ``$<TARGET_FILE_BASE_NAME:tgt,POSTFIX:EXCLUDE>``.
See also the :prop_tgt:OUTPUT_NAME, :prop_tgt:ARCHIVE_OUTPUT_NAME,
:prop_tgt:LIBRARY_OUTPUT_NAME and :prop_tgt:RUNTIME_OUTPUT_NAME
target properties, their configuration-specific variants
:prop_tgt:OUTPUT_NAME_<CONFIG>, :prop_tgt:ARCHIVE_OUTPUT_NAME_<CONFIG>,
:prop_tgt:LIBRARY_OUTPUT_NAME_<CONFIG> and
:prop_tgt:RUNTIME_OUTPUT_NAME_<CONFIG>, and
the :prop_tgt:<CONFIG>_POSTFIX and :prop_tgt:DEBUG_POSTFIX target
properties.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_FILE_PREFIX:tgt>
.. versionadded:: 3.15
Prefix of the tgt filename (such as lib).
See also the :prop_tgt:PREFIX target property.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_FILE_SUFFIX:tgt>
.. versionadded:: 3.15
Suffix of the tgt filename (extension such as .so or .exe).
See also the :prop_tgt:SUFFIX target property.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<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 :policy:CMP0112).
.. genex:: $<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 :policy:CMP0112).
.. genex:: $<TARGET_IMPORT_FILE:tgt>
.. versionadded:: 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 :prop_tgt:ENABLE_EXPORTS property.
This expands to an empty string when there is no import file associated with the target.
.. genex:: $<TARGET_IMPORT_FILE_BASE_NAME:tgt[,POSTFIX:(INCLUDE|EXCLUDE)]>
.. versionadded:: 3.27
.. versionadded:: 4.2
The POSTFIX option can be used to control the inclusion or not
of the :prop_tgt:<CONFIG>_POSTFIX target property value as part of the
base name. The default is POSTFIX:INCLUDE.
Base name of the linker import file of the target tgt without prefix or
suffix and, optionally, postfix.
For example, if the target file name is libbase_postfix.tbd, the base
name is:
* ``base_postfix`` for ``$<TARGET_IMPORT_FILE_BASE_NAME:tgt>`` or
``$<TARGET_IMPORT_FILE_BASE_NAME:tgt,POSTFIX:INCLUDE>``.
* ``base`` for ``$<TARGET_IMPORT_FILE_BASE_NAME:tgt,POSTFIX:EXCLUDE>``.
See also the :prop_tgt:OUTPUT_NAME and :prop_tgt:ARCHIVE_OUTPUT_NAME
target properties, their configuration-specific variants
:prop_tgt:OUTPUT_NAME_<CONFIG> and
:prop_tgt:ARCHIVE_OUTPUT_NAME_<CONFIG>, and
the :prop_tgt:<CONFIG>_POSTFIX and :prop_tgt:DEBUG_POSTFIX target
properties.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_IMPORT_FILE_PREFIX:tgt>
.. versionadded:: 3.27
Prefix of the import file of the target tgt.
See also the :prop_tgt:IMPORT_PREFIX target property.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_IMPORT_FILE_SUFFIX:tgt>
.. versionadded:: 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 :prop_tgt:IMPORT_SUFFIX target property.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_IMPORT_FILE_NAME:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_IMPORT_FILE_DIR:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_LINKER_FILE:tgt>
File used when linking to the tgt target. This will usually
be the library that tgt represents (.a, .lib, .so),
but for a shared library on DLL platforms, it would be the .lib
import library associated with the DLL.
.. versionadded:: 3.27
On macOS, it could be the .tbd import file associated with the shared
library, depending on the value of the :prop_tgt:ENABLE_EXPORTS property.
This generator expression is equivalent to
:genex:$<TARGET_LINKER_LIBRARY_FILE> or
:genex:$<TARGET_LINKER_IMPORT_FILE> generator expressions, depending on the
characteristics of the target and the platform.
.. genex:: $<TARGET_LINKER_FILE_BASE_NAME:tgt[,POSTFIX:(INCLUDE|EXCLUDE)]>
.. versionadded:: 3.15
.. versionadded:: 4.2
The POSTFIX option can be used to control the inclusion or not
of the :prop_tgt:<CONFIG>_POSTFIX target property value as part of the
base name. The default is POSTFIX:INCLUDE.
Base name of file used to link the target tgt, i.e.
:genex:$<TARGET_LINKER_FILE_NAME:tgt> without prefix and suffix, and,
optionally, postfix.
For example, if the target file name is libbase_postfix.a, the base name
is:
* ``base_postfix`` for ``$<TARGET_LINKER_FILE_BASE_NAME:tgt>`` or
``$<TARGET_LINKER_FILE_BASE_NAME:tgt,POSTFIX:INCLUDE>``.
* ``base`` for ``$<TARGET_LINKER_FILE_BASE_NAME:tgt,POSTFIX:EXCLUDE>``.
See also the :prop_tgt:OUTPUT_NAME, :prop_tgt:ARCHIVE_OUTPUT_NAME,
and :prop_tgt:LIBRARY_OUTPUT_NAME target properties, their
configuration-specific variants :prop_tgt:OUTPUT_NAME_<CONFIG>,
:prop_tgt:ARCHIVE_OUTPUT_NAME_<CONFIG> and
:prop_tgt:LIBRARY_OUTPUT_NAME_<CONFIG>, and
the :prop_tgt:<CONFIG>_POSTFIX and :prop_tgt:DEBUG_POSTFIX target
properties.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_LINKER_FILE_PREFIX:tgt>
.. versionadded:: 3.15
Prefix of file used to link target tgt.
See also the :prop_tgt:PREFIX and :prop_tgt:IMPORT_PREFIX target
properties.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_LINKER_FILE_SUFFIX:tgt>
.. versionadded:: 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 :prop_tgt:SUFFIX and :prop_tgt:IMPORT_SUFFIX target
properties.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<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 :policy:CMP0112).
.. genex:: $<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 :policy:CMP0112).
.. genex:: $<TARGET_LINKER_LIBRARY_FILE:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_LINKER_LIBRARY_FILE_BASE_NAME:tgt[,POSTFIX:(INCLUDE|EXCLUDE)]>
.. versionadded:: 3.27
.. versionadded:: 4.2
The POSTFIX option can be used to control the inclusion or not
of the :prop_tgt:<CONFIG>_POSTFIX target property value as part of the
base name. The default is POSTFIX:INCLUDE.
Base name of library file used to link the target tgt, i.e.
:genex:$<TARGET_LINKER_LIBRARY_FILE_NAME:tgt> without prefix and
suffix,and, optionally, postfix.
For example, if the target file name is libbase_postfix.a, the base name
is:
* ``base_postfix`` for ``$<TARGET_LINKER_LIBRARY_FILE_BASE_NAME:tgt>`` or
``$<TARGET_LINKER_LIBRARY_FILE_BASE_NAME:tgt,POSTFIX:INCLUDE>``.
* ``base`` for
``$<TARGET_LINKER_LIBRARY_FILE_BASE_NAME:tgt,POSTFIX:EXCLUDE>``.
See also the :prop_tgt:OUTPUT_NAME, :prop_tgt:ARCHIVE_OUTPUT_NAME,
and :prop_tgt:LIBRARY_OUTPUT_NAME target properties, their
configuration-specific variants :prop_tgt:OUTPUT_NAME_<CONFIG>,
:prop_tgt:ARCHIVE_OUTPUT_NAME_<CONFIG> and
:prop_tgt:LIBRARY_OUTPUT_NAME_<CONFIG>, and
the :prop_tgt:<CONFIG>_POSTFIX and :prop_tgt:DEBUG_POSTFIX target
properties.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_LINKER_LIBRARY_FILE_PREFIX:tgt>
.. versionadded:: 3.27
Prefix of the library file used to link target tgt.
See also the :prop_tgt:PREFIX target property.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_LINKER_LIBRARY_FILE_SUFFIX:tgt>
.. versionadded:: 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 :prop_tgt:SUFFIX target property.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_LINKER_LIBRARY_FILE_NAME:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_LINKER_LIBRARY_FILE_DIR:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_LINKER_IMPORT_FILE:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_LINKER_IMPORT_FILE_BASE_NAME:tgt[,POSTFIX:(INCLUDE|EXCLUDE)]>
.. versionadded:: 3.27
.. versionadded:: 4.2
The POSTFIX option can be used to control the inclusion or not
of the :prop_tgt:<CONFIG>_POSTFIX target property value as part of the
base name. The default is POSTFIX:INCLUDE.
Base name of the import file used to link the target tgt, i.e.
:genex:$<TARGET_LINKER_IMPORT_FILE_NAME:tgt> without prefix and suffix,
and, optionally, postfix.
For example, if the target file name is libbase_postfix.tbd, the base
name is
* ``base_postfix`` for ``$<TARGET_LINKER_IMPORT_FILE_BASE_NAME:tgt>`` or
``$<TARGET_LINKER_IMPORT_FILE_BASE_NAME:tgt,POSTFIX:INCLUDE>``.
* ``base`` for
``$<TARGET_LINKER_IMPORT_FILE_BASE_NAME:tgt,POSTFIX:EXCLUDE>``.
See also the :prop_tgt:OUTPUT_NAME and :prop_tgt:ARCHIVE_OUTPUT_NAME,
target properties, their configuration-specific variants
:prop_tgt:OUTPUT_NAME_<CONFIG> and
:prop_tgt:ARCHIVE_OUTPUT_NAME_<CONFIG>, and
the :prop_tgt:<CONFIG>_POSTFIX and :prop_tgt:DEBUG_POSTFIX target
properties.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_LINKER_IMPORT_FILE_PREFIX:tgt>
.. versionadded:: 3.27
Prefix of the import file used to link target tgt.
See also the :prop_tgt:IMPORT_PREFIX target property.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_LINKER_IMPORT_FILE_SUFFIX:tgt>
.. versionadded:: 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 :prop_tgt:IMPORT_SUFFIX target property.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_LINKER_IMPORT_FILE_NAME:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_LINKER_IMPORT_FILE_DIR:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_SONAME_FILE:tgt>
File with soname (.so.3) where tgt is the name of a target.
.. genex:: $<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 :policy:CMP0112).
.. genex:: $<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 :policy:CMP0112).
.. genex:: $<TARGET_SONAME_IMPORT_FILE:tgt>
.. versionadded:: 3.27
Import file with soname (.3.tbd) where tgt is the name of a target.
.. genex:: $<TARGET_SONAME_IMPORT_FILE_NAME:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_SONAME_IMPORT_FILE_DIR:tgt>
.. versionadded:: 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.
.. genex:: $<TARGET_PDB_FILE:tgt>
.. versionadded:: 3.1
Full path to the linker generated program database file (.pdb)
where tgt is the name of a target.
.. versionchanged:: 4.2
The postfix, as specified by :prop_tgt:DEBUG_POSTFIX or
:prop_tgt:<CONFIG>_POSTFIX target properties, is always included in the
PDB file name. See the policy :policy:CMP0202.
See also the :prop_tgt:PDB_NAME and :prop_tgt:PDB_OUTPUT_DIRECTORY
target properties and their configuration specific variants
:prop_tgt:PDB_NAME_<CONFIG> and :prop_tgt:PDB_OUTPUT_DIRECTORY_<CONFIG>.
.. genex:: $<TARGET_PDB_FILE_BASE_NAME:tgt[,POSTFIX:(INCLUDE|EXCLUDE)]>
.. versionadded:: 3.15
Base name of the linker generated program database file (.pdb)
where tgt is the name of a target.
.. versionadded:: 4.2
The POSTFIX option can be used to control the inclusion or not
of the :prop_tgt:<CONFIG>_POSTFIX target property value as part of the
base name. The default is POSTFIX:INCLUDE.
.. versionchanged:: 4.2
The postfix, as specified by :prop_tgt:DEBUG_POSTFIX or
:prop_tgt:<CONFIG>_POSTFIX target properties, is always included in the
PDB base name, except if the POSTFIX option has the value
EXCLUDE. See the policy :policy:CMP0202.
The base name corresponds to the target PDB file name (see
$<TARGET_PDB_FILE_NAME:tgt>) without prefix and suffix, and, optionally,
postfix. For example, if the target file name is base_postfix.pdb, the
base name is
* ``base_postfix`` for ``$<TARGET_PDB_FILE_BASE_NAME:tgt>`` or
``$<TARGET_PDB_FILE_BASE_NAME:tgt,POSTFIX:INCLUDE>``.
* ``base`` for ``$<TARGET_PDB_FILE_BASE_NAME:tgt,POSTFIX:EXCLUDE>``.
See also the :prop_tgt:OUTPUT_NAME and :prop_tgt:PDB_NAME target
properties, their configuration-specific variants
:prop_tgt:OUTPUT_NAME_<CONFIG> and :prop_tgt:PDB_NAME_<CONFIG>, and the
:prop_tgt:<CONFIG>_POSTFIX and :prop_tgt:DEBUG_POSTFIX target properties.
Note that tgt is not added as a dependency of the target this
expression is evaluated on.
.. genex:: $<TARGET_PDB_FILE_NAME:tgt>
.. versionadded:: 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 :policy:CMP0112).
.. genex:: $<TARGET_PDB_FILE_DIR:tgt>
.. versionadded:: 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 :policy:CMP0112).
.. genex:: $<TARGET_BUNDLE_DIR:tgt>
.. versionadded:: 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 :policy:CMP0112).
.. genex:: $<TARGET_BUNDLE_DIR_NAME:tgt>
.. versionadded:: 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 :policy:CMP0112).
.. genex:: $<TARGET_BUNDLE_CONTENT_DIR:tgt>
.. versionadded:: 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 :policy:CMP0112).
.. genex:: $<TARGET_OBJECTS:tgt>
.. versionadded:: 3.1
List of objects resulting from building tgt. This would typically be
used on :ref:object library <Object Libraries> targets.
.. genex:: $<TARGET_RUNTIME_DLLS:tgt>
.. versionadded:: 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
:genex: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 :option:cmake -E copy -t <cmake-E copy> command. For example:
.. code-block:: cmake
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::
:ref:`Imported Targets` are supported only if they know the location
of their ``.dll`` files. An imported ``SHARED`` library must have
:prop_tgt:`IMPORTED_LOCATION` set to its ``.dll`` file. See the
:ref:`add_library imported libraries <add_library imported libraries>`
section for details. Many :ref:`Find Modules` produce imported targets
with the ``UNKNOWN`` type and therefore will be ignored.
On platforms that support runtime paths (RPATH), refer to the
:prop_tgt:INSTALL_RPATH target property.
On Apple platforms, refer to the :prop_tgt:INSTALL_NAME_DIR target property.
.. genex:: $<TARGET_RUNTIME_DLL_DIRS:tgt>
.. versionadded:: 3.27
List of the directories which contain the DLLs that the target depends on at
runtime (see :genex: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
:command:file(GENERATE) which sets the PATH environment variable accordingly.
.. genex:: $<TARGET_INTERMEDIATE_DIR:tgt>
.. versionadded:: 4.2
The full path to the directory where intermediate target files, such as object and dependency files, are stored.
.. genex:: $<INSTALL_INTERFACE:...>
Content of ... when the property is exported using
:command:install(EXPORT), and empty otherwise.
.. genex:: $<BUILD_INTERFACE:...>
Content of ... when the property is exported using :command:export, or
when the target is used by another target in the same buildsystem. Expands to
the empty string otherwise.
.. genex:: $<BUILD_LOCAL_INTERFACE:...>
.. versionadded:: 3.26
Content of ... when the target is used by another target in the same
buildsystem. Expands to the empty string otherwise.
.. genex:: $<INSTALL_PREFIX>
Content of the install prefix when the target is exported via
:command:install(EXPORT), or when evaluated in the
:prop_tgt:INSTALL_NAME_DIR property or the INSTALL_NAME_DIR argument of
:command:install(RUNTIME_DEPENDENCY_SET), and empty otherwise.
.. versionchanged:: 3.27
Evaluates to the content of the install prefix
in the code argument of :command:install(CODE) or
the file argument of :command:install(SCRIPT).
.. genex:: $<GENEX_EVAL:expr>
.. versionadded:: 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.
.. genex:: $<TARGET_GENEX_EVAL:tgt,expr>
.. versionadded:: 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:
.. code-block:: cmake
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>:
.. code-block:: cmake
add_custom_target(printFooKeys
COMMAND ${CMAKE_COMMAND} -E
echo $<TARGET_GENEX_EVAL:foo,$<TARGET_PROPERTY:foo,CUSTOM_KEYS>>
)
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.
.. genex:: $<ANGLE-R>
A literal >. Used for example to compare strings that contain a >.
.. genex:: $<COMMA>
A literal ,. Used for example to compare strings which contain a ,.
.. genex:: $<SEMICOLON>
A literal ;. Used to prevent list expansion on an argument with ;.
.. genex:: $<QUOTE>
.. versionadded:: 3.30
A literal ". Used to allow string literal quotes inside a generator expression.
.. genex:: $<CONFIGURATION>
Configuration name. Deprecated since CMake 3.0. Use :genex:CONFIG instead.