Static software defect detection is an active research topic in the domain of software engineering and software security. Along with the increase of software complexity and size, static software defect detection has been applied in both industry and academy to take the benefit of finding defects in C/C++ programs without execution. A large amount of static analysis tools (SATs) for C/C++ have been developed in recent years, and have played an important role in automatically finding defects in various kinds of C/C++ software projects. In spite of this, developers are still having less confidence on SATs mainly due to the high false positive rate that has been an unsolved problem for a long time. This research dives deep into state-of-the-art static analysis tools for C/C++ and figures out why false positives are raised through the approach of running them on Juliet Test Suite and 37 open-source real-world software projects. With insight of the design and implementation details of the selected open-source SATs, the exact reasons of which result in the high false positive rateare found. Moreover, the effort is also made to trace the tendency of development and the future of state-of-the-art open-source C/C++ SATs.