CMAKE_<LANG>_COMPILER_FRONTEND_VARIANT

.. versionadded:: 3.14

Identification string of the compiler frontend variant.

Some compilers have multiple, different frontends for accepting command line options. (For example Clang originally only had a frontend compatible with the GNU compiler but since its port to Windows (Clang-Cl) it now also supports a frontend compatible with MSVC.) When CMake detects such a compiler it sets this variable to what would have been the :variable:CMAKE_<LANG>_COMPILER_ID for the compiler whose frontend it resembles.

.. note:: In other words, this variable describes what command line options and language extensions the compiler frontend expects.

.. versionchanged:: 3.26 This variable is set for GNU, MSVC, and AppleClang compilers that have only one frontend variant.