RCFLAGS
-------

Default compilation flags to be used when compiling ``resource`` files. Will
only be used by CMake on the first configuration to determine ``resource``
default compilation flags, after which the value for ``RCFLAGS`` is stored in
the cache as :variable:`CMAKE_RC_FLAGS <CMAKE_<LANG>_FLAGS>`. For any
configuration run (including the first), the environment variable will be ignored
if the :variable:`CMAKE_RC_FLAGS <CMAKE_<LANG>_FLAGS>` variable is defined.