The International Standard imposes no requirement != The compiler can use flawed logic while making assumptions. By flawed logic I'm reffering to the argument "

The International Standard imposes no requirement != The compiler can use flawed logic while making assumptions. By flawed logic I'm reffering to the argument "this situation is undefined so it never happens", in particular applied to the example of pointer dereferencing: when GCC see a pointer being dereferneced it instantly assumes that it isn't null, so if the programmer later explicitly checks for the value being not null GCC ignores it and doesn't translate that part of the program. This can introduce severe vulnerabilities only because the compiler is trying to do an optimization that I find too much aggressive: it decides not to compile an entire part of a program!