Re: sparse (static analyzer) report

Greg Stark <gsstark(at)mit(dot)edu> writes:
> Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl> writes:
>> Hmm. Well, it showed the multiple incorrect uses of 0 as NULL in
>> dllist.c and other places,

> Incidentally, while it may not be conformant to your style guidelines, use of
> the constant 0 compared to or assigned to a pointer is a perfectly valid ANSI
> spelling for NULL.

Absolutely. But I agree that it is more readable to use NULL when you
mean a null pointer, and 0 when you mean an integer zero. The C
standard may not distinguish these concepts, but I do ;-)

Something that I don't have a real strong feeling about is
if (ptr != NULL)
versus
if (ptr)
I've been known to write both. Can anyone mount a good readability
argument for one over the other?

How about the inverse case,
if (ptr == NULL)
versus
if (!ptr)
Applying a boolean ! to a pointer seems a bit shaky to me, though
it's certainly a common locution.

regards, tom lane