> If you know that p is not NULL then why are you checking for it? These dummy tests can happen if you have a lot of macros for example. It still valid C code

> If you know that p is not NULL then why are you checking for it? These dummy tests can happen if you have a lot of macros for example. It still valid C code as long as p is not NULL. A compiler generating an error on this particular example wouldn't be a correct C compiler. The compiler can reject this code if it can prove that p can be NULL, but in many case that's impossible at compile time. I agree that a warning would be nice though. edit: clarity.