US-CERT Vulnerability Note VU#162289

[Robert Dewar]

Paul Koning wrote:

> That said, it certainly is helpful if the compiler can detect some
> undefined actions and warn about them.  But that doesn't create a duty
> to warn about all of them.

If it were reasonable to require a compiler to generate a warning
for a particular case, the standard would have made it an error.
The whole point in allowing undefined behavior is that in certain
cases, it is too onerous for a compiler to be required to detect
the undefined behavior, so it is not required to do so.