The cxx plugin does not run any analysis tools, thus all reports must be generated externally
C++ Community plugin uses currently cppncss to obtain complexity metrics. Here is how to use it
You may also use -D and -M options to tell cppncss about preprocessor macros.
cppncss -r -v -x -k -f=report.xml <sources>
No complexity measure will be available in sonar if cppncss is not run.