CMake/Help/variable/CMAKE_LANG_SIMULATE_ID.rst

CMAKE_<LANG>_SIMULATE_ID
------------------------

Identification string of "simulated" compiler.

Some compilers simulate other compilers to serve as drop-in
replacements.  When CMake detects such a compiler it sets this
variable to what would have been the CMAKE_<LANG>_COMPILER_ID for the
simulated compiler.