CMAKE_<LANG>_EXTENSIONS

The variations are:

:variable:CMAKE_C_EXTENSIONS
:variable:CMAKE_CXX_EXTENSIONS
:variable:CMAKE_CUDA_EXTENSIONS
:variable:CMAKE_HIP_EXTENSIONS
:variable:CMAKE_OBJC_EXTENSIONS
:variable:CMAKE_OBJCXX_EXTENSIONS

Default values for :prop_tgt:<LANG>_EXTENSIONS target properties if set when a target is created. For the compiler's default setting see :variable:CMAKE_<LANG>_EXTENSIONS_DEFAULT.

For supported CMake versions see the respective pages.

See the :manual:cmake-compile-features(7) manual for information on compile features and a list of supported compilers.