https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81928
Daniel Krügler <daniel.kruegler at googlemail dot com> changed:
What |Removed |Added
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--- Comment #5 from Daniel Krügler <daniel.kruegler at googlemail dot com> ---
(In reply to Matthieu Brucher from comment #4)
> I would agree if the debug and optimized versions had the same behavior.
> They do not. As such there should be a huge warning about the undefined
> behavior.
The test alone is not undefined behaviour. This is like requesting that the
following code has undefined behaviour:
int main()
{
int i = 12;
int* that = &i;
if (!that) {}
}
> And no, it's not valid code, it's an undefined behavior, you can do whatever
> you want with it. Outputting an error is a better solution, even adding a
> warning is. Silently optimizing an undefined behavior away is not.
This argumentation is wrong. There is nothing fundamentally wrong to compare
'this' against null. The only reason to request a warning is because this test
cannot evaluate to true in conforming programs.
