Sanitizers are dynamic testing tools that are based on compile-time instrumentation of code. They can help with the overall stability and security of the system, as well as avoiding undefined behavior. At https://github.com/google/sanitizers, you can find implementations for LLVM (which Clang is based on) and GCC. They address problems with memory access, memory leaks, data races and deadlocks, uninitialized memory use, and undefined behavior.
AddressSanitizer (ASan) protects your code against issues related to memory addressing, such as global-buffer-overflow, use-after-free, or stack-use-after-return. Even though it's one of the fastest solutions of its kind, it still slows down the process about two times. It's best to use it when running tests and doing development but turn it off in production builds. You can turn it on for your builds by adding the -fsanitize=address flag to Clang.
AddressSanitizerLeakSanitizer (LSan) integrates with ASan...