re: NULL pointer arithmetic issues

[matthew green <mrg%eterna.com.au@localhost>]

> It seems to me the proper approach is to teach the tool to accept
> this, and to avoid cluttering the tree with churn to work around the
> tool's deficiency, unless there's actually a serious compelling
> argument -- beyond a language-lawyering troll -- that (char *)NULL + 0
> is meaningfully undefined.
> 
> We already assume, for example, that memset(...,0,...) is the same as
> initialization to null pointers where the object in question is a
> pointer or has pointers as subobjects.
> 
> I think we should treat memcpy(NULL,NULL,0) similarly and tell the
> tool `no, on NetBSD that really is defined and we're not interested in
> hearing about theoretical nasal demons from armchair language
> lawyers'.

well said.  i 100% agree.  these extreme edge-cases of UB
that have a very clear definition don't seem to he helpful
in finding any real class of bugs and only seem to be good
at cluttering up working code.


.mrg.