On Wed, Jan 9, 2019 at 1:29 PM Derek M Jones <derek@xxxxxxxxxxxx> wrote:
>
> Using of 0 in this context does not make the source non-strictly
> conforming.
>
> "An integer constant expression with the value 0, or such an expression
> cast to type void *, is called a null pointer constant."
Completely and utterly irrelevant.
sparse warns about a lot of "conforming" code. That's the _point_.
Sparse warns about bad things. Using an integer 0 when a pointer is
asked for is bad. The fact that it's "legacy C bad" doesn't change
anything.
Using functions without declaring them is "legacy C bad" too. Sparse
will warn about it.
Using an assignment expression in a conditional is "legacy C bad" too.
Sparse will complain about it.
All of those are "strictly conforming" features of C. That doesn't
mean they shouldn't be warned about. Because they are really really
bad ideas.
0 is not a pointer. It's that easy.
The fact that K&R C silently casts it to a special NULL pointer in a
pointer context was understandable - back in the late 1960's. People
got over it. It's historical bad behavior. Don't do it. There are *no*
excuses for doing it.
Linus
