open source auto generation of unit test cases tool for C/C++ in windows/linux

Is there are any open source auto generation of unit test cases tool for C/C++ in windows/linux ?

I couldn't find any open source tool that can auto generate the unit test cases for C and C++ language,it might be in windows or on linux.Please can someone help me out here.

I know there are lots of commercial tools like Parasoft,LDRA ect that can do the job.But i am looking for open source tool.