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1194 lines
40 KiB
1194 lines
40 KiB
.. cmake-manual-description: CMake Generator Expressions
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cmake-generator-expressions(7)
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******************************
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.. only:: html
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.. contents::
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Introduction
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============
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Generator expressions are evaluated during build system generation to produce
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information specific to each build configuration.
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Generator expressions are allowed in the context of many target properties,
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such as :prop_tgt:`LINK_LIBRARIES`, :prop_tgt:`INCLUDE_DIRECTORIES`,
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:prop_tgt:`COMPILE_DEFINITIONS` and others. They may also be used when using
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commands to populate those properties, such as :command:`target_link_libraries`,
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:command:`target_include_directories`, :command:`target_compile_definitions`
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and others.
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They enable conditional linking, conditional definitions used when compiling,
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conditional include directories, and more. The conditions may be based on
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the build configuration, target properties, platform information or any other
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queryable information.
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Generator expressions have the form ``$<...>``. To avoid confusion, this page
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deviates from most of the CMake documentation in that it omits angular brackets
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``<...>`` around placeholders like ``condition``, ``string``, ``target``,
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among others.
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Generator expressions can be nested, as shown in most of the examples below.
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.. _`Boolean Generator Expressions`:
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Boolean Generator Expressions
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=============================
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Boolean expressions evaluate to either ``0`` or ``1``.
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They are typically used to construct the condition in a :ref:`conditional
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generator expression<Conditional Generator Expressions>`.
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Available boolean expressions are:
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Logical Operators
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-----------------
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.. genex:: $<BOOL:string>
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Converts ``string`` to ``0`` or ``1``. Evaluates to ``0`` if any of the
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following is true:
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* ``string`` is empty,
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* ``string`` is a case-insensitive equal of
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``0``, ``FALSE``, ``OFF``, ``N``, ``NO``, ``IGNORE``, or ``NOTFOUND``, or
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* ``string`` ends in the suffix ``-NOTFOUND`` (case-sensitive).
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Otherwise evaluates to ``1``.
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.. genex:: $<AND:conditions>
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where ``conditions`` is a comma-separated list of boolean expressions.
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Evaluates to ``1`` if all conditions are ``1``.
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Otherwise evaluates to ``0``.
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.. genex:: $<OR:conditions>
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where ``conditions`` is a comma-separated list of boolean expressions.
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Evaluates to ``1`` if at least one of the conditions is ``1``.
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Otherwise evaluates to ``0``.
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.. genex:: $<NOT:condition>
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``0`` if ``condition`` is ``1``, else ``1``.
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String Comparisons
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------------------
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.. genex:: $<STREQUAL:string1,string2>
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``1`` if ``string1`` and ``string2`` are equal, else ``0``.
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The comparison is case-sensitive. For a case-insensitive comparison,
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combine with a :ref:`string transforming generator expression
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<String Transforming Generator Expressions>`,
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.. code-block:: cmake
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$<STREQUAL:$<UPPER_CASE:${foo}>,"BAR"> # "1" if ${foo} is any of "BAR", "Bar", "bar", ...
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.. genex:: $<EQUAL:value1,value2>
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``1`` if ``value1`` and ``value2`` are numerically equal, else ``0``.
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.. genex:: $<IN_LIST:string,list>
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.. versionadded:: 3.12
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``1`` if ``string`` is member of the semicolon-separated ``list``, else ``0``.
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Uses case-sensitive comparisons.
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.. genex:: $<VERSION_LESS:v1,v2>
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``1`` if ``v1`` is a version less than ``v2``, else ``0``.
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.. genex:: $<VERSION_GREATER:v1,v2>
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``1`` if ``v1`` is a version greater than ``v2``, else ``0``.
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.. genex:: $<VERSION_EQUAL:v1,v2>
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``1`` if ``v1`` is the same version as ``v2``, else ``0``.
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.. genex:: $<VERSION_LESS_EQUAL:v1,v2>
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.. versionadded:: 3.7
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``1`` if ``v1`` is a version less than or equal to ``v2``, else ``0``.
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.. genex:: $<VERSION_GREATER_EQUAL:v1,v2>
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.. versionadded:: 3.7
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``1`` if ``v1`` is a version greater than or equal to ``v2``, else ``0``.
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Variable Queries
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----------------
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.. genex:: $<TARGET_EXISTS:target>
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.. versionadded:: 3.12
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``1`` if ``target`` exists, else ``0``.
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.. genex:: $<CONFIG:cfgs>
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``1`` if config is any one of the entries in comma-separated list
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``cfgs``, else ``0``. This is a case-insensitive comparison. The mapping in
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:prop_tgt:`MAP_IMPORTED_CONFIG_<CONFIG>` is also considered by this
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expression when it is evaluated on a property on an :prop_tgt:`IMPORTED`
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target.
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.. genex:: $<PLATFORM_ID:platform_ids>
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where ``platform_ids`` is a comma-separated list.
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``1`` if the CMake's platform id matches any one of the entries in
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``platform_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_SYSTEM_NAME` variable.
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.. genex:: $<C_COMPILER_ID:compiler_ids>
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where ``compiler_ids`` is a comma-separated list.
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``1`` if the CMake's compiler id of the C compiler matches any one
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of the entries in ``compiler_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
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.. genex:: $<CXX_COMPILER_ID:compiler_ids>
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where ``compiler_ids`` is a comma-separated list.
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``1`` if the CMake's compiler id of the CXX compiler matches any one
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of the entries in ``compiler_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
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.. genex:: $<CUDA_COMPILER_ID:compiler_ids>
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.. versionadded:: 3.15
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where ``compiler_ids`` is a comma-separated list.
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``1`` if the CMake's compiler id of the CUDA compiler matches any one
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of the entries in ``compiler_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
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.. genex:: $<OBJC_COMPILER_ID:compiler_ids>
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.. versionadded:: 3.16
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where ``compiler_ids`` is a comma-separated list.
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``1`` if the CMake's compiler id of the Objective-C compiler matches any one
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of the entries in ``compiler_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
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.. genex:: $<OBJCXX_COMPILER_ID:compiler_ids>
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.. versionadded:: 3.16
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where ``compiler_ids`` is a comma-separated list.
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``1`` if the CMake's compiler id of the Objective-C++ compiler matches any one
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of the entries in ``compiler_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
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.. genex:: $<Fortran_COMPILER_ID:compiler_ids>
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where ``compiler_ids`` is a comma-separated list.
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``1`` if the CMake's compiler id of the Fortran compiler matches any one
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of the entries in ``compiler_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
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.. genex:: $<HIP_COMPILER_ID:compiler_ids>
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where ``compiler_ids`` is a comma-separated list.
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``1`` if the CMake's compiler id of the HIP compiler matches any one
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of the entries in ``compiler_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
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.. genex:: $<ISPC_COMPILER_ID:compiler_ids>
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.. versionadded:: 3.19
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where ``compiler_ids`` is a comma-separated list.
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``1`` if the CMake's compiler id of the ISPC compiler matches any one
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of the entries in ``compiler_ids``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
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.. genex:: $<C_COMPILER_VERSION:version>
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``1`` if the version of the C compiler matches ``version``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
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.. genex:: $<CXX_COMPILER_VERSION:version>
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``1`` if the version of the CXX compiler matches ``version``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
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.. genex:: $<CUDA_COMPILER_VERSION:version>
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.. versionadded:: 3.15
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``1`` if the version of the CXX compiler matches ``version``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
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.. genex:: $<OBJC_COMPILER_VERSION:version>
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.. versionadded:: 3.16
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``1`` if the version of the OBJC compiler matches ``version``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
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.. genex:: $<OBJCXX_COMPILER_VERSION:version>
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.. versionadded:: 3.16
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``1`` if the version of the OBJCXX compiler matches ``version``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
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.. genex:: $<Fortran_COMPILER_VERSION:version>
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``1`` if the version of the Fortran compiler matches ``version``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
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.. genex:: $<HIP_COMPILER_VERSION:version>
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``1`` if the version of the HIP compiler matches ``version``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
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.. genex:: $<ISPC_COMPILER_VERSION:version>
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.. versionadded:: 3.19
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``1`` if the version of the ISPC compiler matches ``version``, otherwise ``0``.
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See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
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.. genex:: $<TARGET_POLICY:policy>
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``1`` if the ``policy`` was NEW when the 'head' target was created,
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else ``0``. If the ``policy`` was not set, the warning message for the policy
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will be emitted. This generator expression only works for a subset of
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policies.
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.. genex:: $<COMPILE_FEATURES:features>
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.. versionadded:: 3.1
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where ``features`` is a comma-spearated list.
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Evaluates to ``1`` if all of the ``features`` are available for the 'head'
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target, and ``0`` otherwise. If this expression is used while evaluating
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the link implementation of a target and if any dependency transitively
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increases the required :prop_tgt:`C_STANDARD` or :prop_tgt:`CXX_STANDARD`
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for the 'head' target, an error is reported. See the
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:manual:`cmake-compile-features(7)` manual for information on
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compile features and a list of supported compilers.
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.. _`Boolean COMPILE_LANGUAGE Generator Expression`:
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.. genex:: $<COMPILE_LANG_AND_ID:language,compiler_ids>
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.. versionadded:: 3.15
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``1`` when the language used for compilation unit matches ``language`` and
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the CMake's compiler id of the language compiler matches any one of the
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entries in ``compiler_ids``, otherwise ``0``. This expression is a short form
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for the combination of ``$<COMPILE_LANGUAGE:language>`` and
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``$<LANG_COMPILER_ID:compiler_ids>``. This expression may be used to specify
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compile options, compile definitions, and include directories for source files of a
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particular language and compiler combination in a target. For example:
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.. code-block:: cmake
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add_executable(myapp main.cpp foo.c bar.cpp zot.cu)
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target_compile_definitions(myapp
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PRIVATE $<$<COMPILE_LANG_AND_ID:CXX,AppleClang,Clang>:COMPILING_CXX_WITH_CLANG>
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$<$<COMPILE_LANG_AND_ID:CXX,Intel>:COMPILING_CXX_WITH_INTEL>
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$<$<COMPILE_LANG_AND_ID:C,Clang>:COMPILING_C_WITH_CLANG>
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)
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This specifies the use of different compile definitions based on both
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the compiler id and compilation language. This example will have a
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``COMPILING_CXX_WITH_CLANG`` compile definition when Clang is the CXX
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compiler, and ``COMPILING_CXX_WITH_INTEL`` when Intel is the CXX compiler.
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Likewise when the C compiler is Clang it will only see the ``COMPILING_C_WITH_CLANG``
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definition.
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Without the ``COMPILE_LANG_AND_ID`` generator expression the same logic
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would be expressed as:
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.. code-block:: cmake
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target_compile_definitions(myapp
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PRIVATE $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:AppleClang,Clang>>:COMPILING_CXX_WITH_CLANG>
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$<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:Intel>>:COMPILING_CXX_WITH_INTEL>
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$<$<AND:$<COMPILE_LANGUAGE:C>,$<C_COMPILER_ID:Clang>>:COMPILING_C_WITH_CLANG>
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)
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.. genex:: $<COMPILE_LANGUAGE:languages>
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.. versionadded:: 3.3
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``1`` when the language used for compilation unit matches any of the entries
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in ``languages``, otherwise ``0``. This expression may be used to specify
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compile options, compile definitions, and include directories for source files of a
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particular language in a target. For example:
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.. code-block:: cmake
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add_executable(myapp main.cpp foo.c bar.cpp zot.cu)
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target_compile_options(myapp
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PRIVATE $<$<COMPILE_LANGUAGE:CXX>:-fno-exceptions>
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)
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target_compile_definitions(myapp
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PRIVATE $<$<COMPILE_LANGUAGE:CXX>:COMPILING_CXX>
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$<$<COMPILE_LANGUAGE:CUDA>:COMPILING_CUDA>
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)
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target_include_directories(myapp
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PRIVATE $<$<COMPILE_LANGUAGE:CXX,CUDA>:/opt/foo/headers>
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)
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This specifies the use of the ``-fno-exceptions`` compile option,
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``COMPILING_CXX`` compile definition, and ``cxx_headers`` include
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directory for C++ only (compiler id checks elided). It also specifies
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a ``COMPILING_CUDA`` compile definition for CUDA.
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Note that with :ref:`Visual Studio Generators` and :generator:`Xcode` there
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is no way to represent target-wide compile definitions or include directories
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separately for ``C`` and ``CXX`` languages.
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Also, with :ref:`Visual Studio Generators` there is no way to represent
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target-wide flags separately for ``C`` and ``CXX`` languages. Under these
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generators, expressions for both C and C++ sources will be evaluated
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using ``CXX`` if there are any C++ sources and otherwise using ``C``.
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A workaround is to create separate libraries for each source file language
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instead:
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.. code-block:: cmake
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add_library(myapp_c foo.c)
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add_library(myapp_cxx bar.cpp)
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target_compile_options(myapp_cxx PUBLIC -fno-exceptions)
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add_executable(myapp main.cpp)
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target_link_libraries(myapp myapp_c myapp_cxx)
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.. _`Boolean LINK_LANGUAGE Generator Expression`:
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.. genex:: $<LINK_LANG_AND_ID:language,compiler_ids>
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.. versionadded:: 3.18
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``1`` when the language used for link step matches ``language`` and the
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CMake's compiler id of the language linker matches any one of the entries
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in ``compiler_ids``, otherwise ``0``. This expression is a short form for the
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combination of ``$<LINK_LANGUAGE:language>`` and
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``$<LANG_COMPILER_ID:compiler_ids>``. This expression may be used to specify
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link libraries, link options, link directories and link dependencies of a
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particular language and linker combination in a target. For example:
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.. code-block:: cmake
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add_library(libC_Clang ...)
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add_library(libCXX_Clang ...)
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add_library(libC_Intel ...)
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add_library(libCXX_Intel ...)
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add_executable(myapp main.c)
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if (CXX_CONFIG)
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target_sources(myapp PRIVATE file.cxx)
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endif()
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target_link_libraries(myapp
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PRIVATE $<$<LINK_LANG_AND_ID:CXX,Clang,AppleClang>:libCXX_Clang>
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$<$<LINK_LANG_AND_ID:C,Clang,AppleClang>:libC_Clang>
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$<$<LINK_LANG_AND_ID:CXX,Intel>:libCXX_Intel>
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$<$<LINK_LANG_AND_ID:C,Intel>:libC_Intel>)
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This specifies the use of different link libraries based on both the
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compiler id and link language. This example will have target ``libCXX_Clang``
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as link dependency when ``Clang`` or ``AppleClang`` is the ``CXX``
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linker, and ``libCXX_Intel`` when ``Intel`` is the ``CXX`` linker.
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Likewise when the ``C`` linker is ``Clang`` or ``AppleClang``, target
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``libC_Clang`` will be added as link dependency and ``libC_Intel`` when
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``Intel`` is the ``C`` linker.
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See :ref:`the note related to
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<Constraints LINK_LANGUAGE Generator Expression>`
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``$<LINK_LANGUAGE:language>`` for constraints about the usage of this
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generator expression.
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.. genex:: $<LINK_LANGUAGE:languages>
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.. versionadded:: 3.18
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``1`` when the language used for link step matches any of the entries
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in ``languages``, otherwise ``0``. This expression may be used to specify
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link libraries, link options, link directories and link dependencies of a
|
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particular language in a target. For example:
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.. code-block:: cmake
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add_library(api_C ...)
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add_library(api_CXX ...)
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add_library(api INTERFACE)
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target_link_options(api INTERFACE $<$<LINK_LANGUAGE:C>:-opt_c>
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$<$<LINK_LANGUAGE:CXX>:-opt_cxx>)
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target_link_libraries(api INTERFACE $<$<LINK_LANGUAGE:C>:api_C>
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$<$<LINK_LANGUAGE:CXX>:api_CXX>)
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add_executable(myapp1 main.c)
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target_link_options(myapp1 PRIVATE api)
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add_executable(myapp2 main.cpp)
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target_link_options(myapp2 PRIVATE api)
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This specifies to use the ``api`` target for linking targets ``myapp1`` and
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``myapp2``. In practice, ``myapp1`` will link with target ``api_C`` and
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option ``-opt_c`` because it will use ``C`` as link language. And ``myapp2``
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will link with ``api_CXX`` and option ``-opt_cxx`` because ``CXX`` will be
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the link language.
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.. _`Constraints LINK_LANGUAGE Generator Expression`:
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.. note::
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To determine the link language of a target, it is required to collect,
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transitively, all the targets which will be linked to it. So, for link
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libraries properties, a double evaluation will be done. During the first
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evaluation, ``$<LINK_LANGUAGE:..>`` expressions will always return ``0``.
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The link language computed after this first pass will be used to do the
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second pass. To avoid inconsistency, it is required that the second pass
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do not change the link language. Moreover, to avoid unexpected
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side-effects, it is required to specify complete entities as part of the
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``$<LINK_LANGUAGE:..>`` expression. For example:
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.. code-block:: cmake
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add_library(lib STATIC file.cxx)
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add_library(libother STATIC file.c)
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# 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:: $<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:: $<HOST_LINK:list>
|
|
|
|
.. versionadded:: 3.18
|
|
|
|
Returns the list if it is the normal link step, an empty list otherwise.
|
|
This expression is mainly useful when a device link step is also involved
|
|
(see ``$<DEVICE_LINK:list>`` generator expression). This expression can only
|
|
be used to specify link options.
|
|
|
|
String-Valued Generator Expressions
|
|
===================================
|
|
|
|
These expressions expand to some string.
|
|
For example,
|
|
|
|
.. code-block:: cmake
|
|
|
|
include_directories(/usr/include/$<CXX_COMPILER_ID>/)
|
|
|
|
expands to ``/usr/include/GNU/`` or ``/usr/include/Clang/`` etc, depending on
|
|
the compiler identifier.
|
|
|
|
String-valued expressions may also be combined with other expressions.
|
|
Here an example for a string-valued expression within a boolean expressions
|
|
within a conditional expression:
|
|
|
|
.. code-block:: cmake
|
|
|
|
$<$<VERSION_LESS:$<CXX_COMPILER_VERSION>,4.2.0>:OLD_COMPILER>
|
|
|
|
expands to ``OLD_COMPILER`` if the
|
|
:variable:`CMAKE_CXX_COMPILER_VERSION <CMAKE_<LANG>_COMPILER_VERSION>` is less
|
|
than 4.2.0.
|
|
|
|
And here two nested string-valued expressions:
|
|
|
|
.. code-block:: cmake
|
|
|
|
-I$<JOIN:$<TARGET_PROPERTY:INCLUDE_DIRECTORIES>, -I>
|
|
|
|
generates a string of the entries in the :prop_tgt:`INCLUDE_DIRECTORIES` target
|
|
property with each entry preceded by ``-I``.
|
|
|
|
Expanding on the previous example, if one first wants to check if the
|
|
``INCLUDE_DIRECTORIES`` property is non-empty, then it is advisable to
|
|
introduce a helper variable to keep the code readable:
|
|
|
|
.. code-block:: cmake
|
|
|
|
set(prop "$<TARGET_PROPERTY:INCLUDE_DIRECTORIES>") # helper variable
|
|
$<$<BOOL:${prop}>:-I$<JOIN:${prop}, -I>>
|
|
|
|
The following string-valued generator expressions are available:
|
|
|
|
Escaped Characters
|
|
------------------
|
|
|
|
String literals to escape the special meaning a character would otherwise have:
|
|
|
|
.. 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 ``;``.
|
|
|
|
.. _`Conditional Generator Expressions`:
|
|
|
|
Conditional Expressions
|
|
-----------------------
|
|
|
|
Conditional generator expressions depend on a boolean condition
|
|
that must be ``0`` or ``1``.
|
|
|
|
.. genex:: $<condition:true_string>
|
|
|
|
Evaluates to ``true_string`` if ``condition`` is ``1``.
|
|
Otherwise evaluates to the empty string.
|
|
|
|
.. genex:: $<IF:condition,true_string,false_string>
|
|
|
|
.. versionadded:: 3.8
|
|
|
|
Evaluates to ``true_string`` if ``condition`` is ``1``.
|
|
Otherwise evaluates to ``false_string``.
|
|
|
|
Typically, the ``condition`` is a :ref:`boolean generator expression
|
|
<Boolean Generator Expressions>`. For instance,
|
|
|
|
.. code-block:: cmake
|
|
|
|
$<$<CONFIG:Debug>:DEBUG_MODE>
|
|
|
|
expands to ``DEBUG_MODE`` when the ``Debug`` configuration is used, and
|
|
otherwise expands to the empty string.
|
|
|
|
.. _`String Transforming Generator Expressions`:
|
|
|
|
String Transformations
|
|
----------------------
|
|
|
|
.. genex:: $<JOIN:list,string>
|
|
|
|
Joins the list with the content of ``string``.
|
|
|
|
.. genex:: $<REMOVE_DUPLICATES:list>
|
|
|
|
.. versionadded:: 3.15
|
|
|
|
Removes duplicated items in the given ``list``.
|
|
|
|
.. genex:: $<FILTER:list,INCLUDE|EXCLUDE,regex>
|
|
|
|
.. versionadded:: 3.15
|
|
|
|
Includes or removes items from ``list`` that match the regular expression ``regex``.
|
|
|
|
.. genex:: $<LOWER_CASE:string>
|
|
|
|
Content of ``string`` converted to lower case.
|
|
|
|
.. genex:: $<UPPER_CASE:string>
|
|
|
|
Content of ``string`` converted to upper case.
|
|
|
|
.. 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>>
|
|
)
|
|
|
|
Variable Queries
|
|
----------------
|
|
|
|
.. genex:: $<CONFIG>
|
|
|
|
Configuration name.
|
|
|
|
.. genex:: $<CONFIGURATION>
|
|
|
|
Configuration name. Deprecated since CMake 3.0. Use ``CONFIG`` instead.
|
|
|
|
.. genex:: $<PLATFORM_ID>
|
|
|
|
The current system's CMake platform id.
|
|
See also the :variable:`CMAKE_SYSTEM_NAME` variable.
|
|
|
|
.. genex:: $<C_COMPILER_ID>
|
|
|
|
The CMake's compiler id of the C compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
|
|
|
|
.. genex:: $<CXX_COMPILER_ID>
|
|
|
|
The CMake's compiler id of the CXX compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
|
|
|
|
.. genex:: $<CUDA_COMPILER_ID>
|
|
|
|
The CMake's compiler id of the CUDA compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
|
|
|
|
.. genex:: $<OBJC_COMPILER_ID>
|
|
|
|
.. versionadded:: 3.16
|
|
|
|
The CMake's compiler id of the OBJC compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
|
|
|
|
.. genex:: $<OBJCXX_COMPILER_ID>
|
|
|
|
.. versionadded:: 3.16
|
|
|
|
The CMake's compiler id of the OBJCXX compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
|
|
|
|
.. genex:: $<Fortran_COMPILER_ID>
|
|
|
|
The CMake's compiler id of the Fortran compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
|
|
|
|
.. genex:: $<HIP_COMPILER_ID>
|
|
|
|
The CMake's compiler id of the HIP compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
|
|
|
|
.. genex:: $<ISPC_COMPILER_ID>
|
|
|
|
.. versionadded:: 3.19
|
|
|
|
The CMake's compiler id of the ISPC compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
|
|
|
|
.. genex:: $<C_COMPILER_VERSION>
|
|
|
|
The version of the C compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
|
|
|
|
.. genex:: $<CXX_COMPILER_VERSION>
|
|
|
|
The version of the CXX compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
|
|
|
|
.. genex:: $<CUDA_COMPILER_VERSION>
|
|
|
|
The version of the CUDA compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
|
|
|
|
.. genex:: $<OBJC_COMPILER_VERSION>
|
|
|
|
.. versionadded:: 3.16
|
|
|
|
The version of the OBJC compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
|
|
|
|
.. genex:: $<OBJCXX_COMPILER_VERSION>
|
|
|
|
.. versionadded:: 3.16
|
|
|
|
The version of the OBJCXX compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
|
|
|
|
.. genex:: $<Fortran_COMPILER_VERSION>
|
|
|
|
The version of the Fortran compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
|
|
|
|
.. genex:: $<HIP_COMPILER_VERSION>
|
|
|
|
The version of the HIP compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
|
|
|
|
.. genex:: $<ISPC_COMPILER_VERSION>
|
|
|
|
.. versionadded:: 3.19
|
|
|
|
The version of the ISPC compiler used.
|
|
See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
|
|
|
|
.. genex:: $<COMPILE_LANGUAGE>
|
|
|
|
.. versionadded:: 3.3
|
|
|
|
The compile language of source files when evaluating compile options.
|
|
See :ref:`the related boolean expression
|
|
<Boolean COMPILE_LANGUAGE Generator Expression>`
|
|
``$<COMPILE_LANGUAGE:language>``
|
|
for notes about the portability of this generator expression.
|
|
|
|
.. genex:: $<LINK_LANGUAGE>
|
|
|
|
.. versionadded:: 3.18
|
|
|
|
The link language of target when evaluating link options.
|
|
See :ref:`the related boolean expression
|
|
<Boolean LINK_LANGUAGE Generator Expression>` ``$<LINK_LANGUAGE:language>``
|
|
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.
|
|
|
|
.. _`Target-Dependent Queries`:
|
|
|
|
Target-Dependent Queries
|
|
------------------------
|
|
|
|
These queries refer to a target ``tgt``. This can be any runtime artifact,
|
|
namely:
|
|
|
|
* an executable target created by :command:`add_executable`
|
|
* a shared library target (``.so``, ``.dll`` but not their ``.lib`` import library)
|
|
created by :command:`add_library`
|
|
* a static library target created by :command:`add_library`
|
|
|
|
In the following, "the ``tgt`` filename" means the name of the ``tgt``
|
|
binary file. This has to be distinguished from "the target name",
|
|
which is just the string ``tgt``.
|
|
|
|
.. 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_FILE:tgt>
|
|
|
|
Full path to the ``tgt`` binary file.
|
|
|
|
.. genex:: $<TARGET_FILE_BASE_NAME:tgt>
|
|
|
|
.. versionadded:: 3.15
|
|
|
|
Base name of ``tgt``, i.e. ``$<TARGET_FILE_NAME:tgt>`` without prefix and
|
|
suffix.
|
|
For example, if the ``tgt`` filename is ``libbase.so``, the base name is ``base``.
|
|
|
|
See also the :prop_tgt:`OUTPUT_NAME`, :prop_tgt:`ARCHIVE_OUTPUT_NAME`,
|
|
:prop_tgt:`LIBRARY_OUTPUT_NAME` and :prop_tgt:`RUNTIME_OUTPUT_NAME`
|
|
target properties and 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>`.
|
|
|
|
The :prop_tgt:`<CONFIG>_POSTFIX` and :prop_tgt:`DEBUG_POSTFIX` target
|
|
properties can also be considered.
|
|
|
|
Note that ``tgt`` is not added as a dependency of the target this
|
|
expression is evaluated on.
|
|
|
|
.. 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_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.
|
|
|
|
.. genex:: $<TARGET_LINKER_FILE_BASE_NAME:tgt>
|
|
|
|
.. versionadded:: 3.15
|
|
|
|
Base name of file used to link the target ``tgt``, i.e.
|
|
``$<TARGET_LINKER_FILE_NAME:tgt>`` without prefix and suffix. For example,
|
|
if target file name is ``libbase.a``, the base name is ``base``.
|
|
|
|
See also the :prop_tgt:`OUTPUT_NAME`, :prop_tgt:`ARCHIVE_OUTPUT_NAME`,
|
|
and :prop_tgt:`LIBRARY_OUTPUT_NAME` target properties and their configuration
|
|
specific variants :prop_tgt:`OUTPUT_NAME_<CONFIG>`,
|
|
:prop_tgt:`ARCHIVE_OUTPUT_NAME_<CONFIG>` and
|
|
:prop_tgt:`LIBRARY_OUTPUT_NAME_<CONFIG>`.
|
|
|
|
The :prop_tgt:`<CONFIG>_POSTFIX` and :prop_tgt:`DEBUG_POSTFIX` target
|
|
properties can also be considered.
|
|
|
|
Note that ``tgt`` is not added as a dependency of the target this
|
|
expression is evaluated on.
|
|
|
|
.. 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_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 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_PDB_FILE:tgt>
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
Full path to the linker generated program database file (.pdb)
|
|
where ``tgt`` is the name of a target.
|
|
|
|
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:: $<TARGET_PDB_FILE_BASE_NAME:tgt>
|
|
|
|
.. versionadded:: 3.15
|
|
|
|
Base name of the linker generated program database file (.pdb)
|
|
where ``tgt`` is the name of a target.
|
|
|
|
The base name corresponds to the target PDB file name (see
|
|
``$<TARGET_PDB_FILE_NAME:tgt>``) without prefix and suffix. For example,
|
|
if target file name is ``base.pdb``, the base name is ``base``.
|
|
|
|
See also the :prop_tgt:`PDB_NAME` target property and its configuration
|
|
specific variant :prop_tgt:`PDB_NAME_<CONFIG>`.
|
|
|
|
The :prop_tgt:`<CONFIG>_POSTFIX` and :prop_tgt:`DEBUG_POSTFIX` target
|
|
properties can also be considered.
|
|
|
|
Note that ``tgt`` is not added as a dependency of the target this
|
|
expression is evaluated on.
|
|
|
|
.. 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 (``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 ``my.app/Contents``, ``my.framework``,
|
|
or ``my.bundle/Contents``. For all other SDKs (e.g. iOS) it leads to
|
|
``my.app``, ``my.framework``, or ``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_PROPERTY:tgt,prop>
|
|
|
|
Value of the property ``prop`` on the target ``tgt``.
|
|
|
|
Note that ``tgt`` is not added as a dependency of the target this
|
|
expression is evaluated on.
|
|
|
|
.. genex:: $<TARGET_PROPERTY:prop>
|
|
|
|
Value of the property ``prop`` on the target for which the expression
|
|
is being evaluated. Note that for generator expressions in
|
|
:ref:`Target Usage Requirements` this is the consuming target rather
|
|
than the target specifying the requirement.
|
|
|
|
.. 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`` and ``MODULE`` 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, it 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. 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 $<TARGET_RUNTIME_DLLS:exe> $<TARGET_FILE_DIR:exe>
|
|
COMMAND_EXPAND_LISTS
|
|
)
|
|
|
|
.. note::
|
|
|
|
:ref:`Imported Targets` are supported only if they know the location
|
|
of their ``.dll`` files. An imported ``SHARED`` or ``MODULE`` 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.
|
|
|
|
.. 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.
|
|
|
|
Output-Related Expressions
|
|
--------------------------
|
|
|
|
.. genex:: $<TARGET_NAME:...>
|
|
|
|
Marks ``...`` as being the name of a target. This is required if exporting
|
|
targets to multiple dependent export sets. The ``...`` must be a literal
|
|
name of a target- it may not contain generator expressions.
|
|
|
|
.. genex:: $<LINK_ONLY:...>
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
Content of ``...`` except when evaluated in a link interface while
|
|
propagating :ref:`Target Usage Requirements`, in which case it is the
|
|
empty string.
|
|
Intended for use only in an :prop_tgt:`INTERFACE_LINK_LIBRARIES` target
|
|
property, perhaps via the :command:`target_link_libraries` command,
|
|
to specify private link dependencies without other usage requirements.
|
|
|
|
.. 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:: $<MAKE_C_IDENTIFIER:...>
|
|
|
|
Content of ``...`` converted to a C identifier. The conversion follows the
|
|
same behavior as :command:`string(MAKE_C_IDENTIFIER)`.
|
|
|
|
.. genex:: $<TARGET_OBJECTS:objLib>
|
|
|
|
.. versionadded:: 3.1
|
|
|
|
List of objects resulting from build of ``objLib``.
|
|
|
|
.. 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:: $<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.
|
|
|
|
Debugging
|
|
=========
|
|
|
|
Since generator expressions are evaluated during generation of the buildsystem,
|
|
and not during processing of ``CMakeLists.txt`` files, it is not possible to
|
|
inspect their result with the :command:`message()` command.
|
|
|
|
One possible way to generate debug messages is to add a custom target,
|
|
|
|
.. code-block:: cmake
|
|
|
|
add_custom_target(genexdebug COMMAND ${CMAKE_COMMAND} -E echo "$<...>")
|
|
|
|
The shell command ``make genexdebug`` (invoked after execution of ``cmake``)
|
|
would then print the result of ``$<...>``.
|
|
|
|
Another way is to write debug messages to a file:
|
|
|
|
.. code-block:: cmake
|
|
|
|
file(GENERATE OUTPUT filename CONTENT "$<...>")
|