Clang is a C/C++ compiler fronted which parses C++ source code. There is a lot of tools based on Clang that can assist you in writing or debugging C++ and Qt code. The first part of this talk will introduce you to existing tools such as the sanitizers, static analyzer, clang-tidy, and clazy. These tools help you to find bugs or refactor big code bases. We will have demo on how to use them and what are they good for. The second part will teach you how to extends these tools to work well with your own code bases. We will see how we can create a plugin that does certain checks to ensure the quality of your code and enforce some of the policies.