Re: [PATCH 3/9] cppcheck: Suppress constParameterCallback errors

[Stefano Brivio <sbrivio@redhat.com>]

On Sat, 8 Jun 2024 16:32:22 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> On Fri, Jun 07, 2024 at 08:49:40PM +0200, Stefano Brivio wrote:
> > On Thu,  6 Jun 2024 20:09:43 +1000
> > David Gibson <david@gibson.dropbear.id.au> wrote:
> >   
> > > We have several functions which are used as callbacks for NS_CALL() which
> > > only read their void * parameter, they don't write it.  The new
> > > constParameterCallback warning in cppcheck 2.14.1 complains that this
> > > parameter could be const void *, also pointing out that that would require
> > > casting the function pointer when used as a callback.
> > > 
> > > Casting the function pointers seems substantially uglier than using a
> > > non-const void * as the parameter, especially since in each case we cast
> > > the void * to a const pointer of specific type immediately.  So, suppress
> > > that error from cppcheck.
> > > 
> > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> > > ---
> > >  Makefile | 1 +
> > >  1 file changed, 1 insertion(+)
> > > 
> > > diff --git a/Makefile b/Makefile
> > > index 8ea17576..22f05813 100644
> > > --- a/Makefile
> > > +++ b/Makefile
> > > @@ -314,5 +314,6 @@ cppcheck: $(SRCS) $(HEADERS)
> > >  	$(SYSTEM_INCLUDES:%=--suppress=unmatchedSuppression:%/*)	\
> > >  	--inline-suppr							\
> > >  	--suppress=unusedStructMember					\
> > > +	--suppress=constParameterCallback				\  
> > 
> > On versions before 2.14, this now raises an unmatchedSuppression... I'm
> > not sure how to deal with this. Should we give up and just add a
> > --suppress=unmatchedSuppression for all the source files? I can't think
> > of anything better at the moment.  
> 
> No, I don't think we want to do that, that's likely to leave stale
> suppressions about.
> 
> Although it logically makes sense to suppress this globally, there are
> only three spots it actually occurs, so I'll rewrite to suppress in
> just those places, along with a similarly local unmatchedSuppression
> suppression.

Oh, you're right, I instinctively thought it would be a much bigger
mess, I didn't even try.

> > I applied the rest of the series, just not this patch.  
> 
> Nice.. although this was the only one actually blocking other work.

...of course. :) I just applied the new patch.

-- 
Stefano