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[Frama-c-discuss] memset and non-chars

On Sun, Sep 06, 2015 at 02:24:35PM +0200, David MENTRÉ wrote:
> Le 2015-09-06 14:18, David MENTRÉ a écrit :
> >Possible explanation: memset() expects char and giving to it violate
> >this assumption.
> 
> ... and giving to it integer violates this assumption.
> 
> 
> >You have some warnings. I cannot say if they are harmful or not.
> >
> >kurt-memset.c:9:[wp] warning: Cast with incompatible pointers types
> >(source: b*) (target: sint8*)
> >kurt-memset.c:7:[wp] warning: Cast with incompatible pointers types
> >(source: sint32*) (target: sint8*)
> 
> Apparently, it could be harmful:
> 
> https://lists.gforge.inria.fr/pipermail/frama-c-discuss/2014-June/004465.html
> 
> My suggestion might not be that good. :-)

Well, memset() takes a void *.  The C standard also allows you to
cast that to a char *, which is probably what memset() will use
internally since you can't use void * directly.  So it seems to me
that memset is always problematic for the Typed+cast model.  And I
can someone understand it that it has problems with it.  It would
of course be nice that it could deal with it.

But the code I'm looking at seems to like to use memset() on
structs so that not all individual members of a struct need to be
set to 0 but that you can do it with 1 call.


Kurt