Re: [Qemu-devel] [PATCH] scripts: add sample model file for Coverity Scan

[Paolo Bonzini]

Il 19/03/2014 10:08, Markus Armbruster ha scritto:
> > It probably would make static analysis a bit less powerful or will
> > return more false positives.  The NULL return for realloc (in the
> > "free" case) already causes some.  So I'm undecided between a more
> > correct model and a more selective one (with a fat comment).
>
> I can't see how lying to the analyzer could make it more powerful :)
> It can, however, suppress false positives.  Scan and find out how many?

Full model (g_malloc returns NULL for 0 argument) => 750 defects

Posted model (g_malloc never returns NULL)        => 702 defects
                -59 NULL_RETURNS defects
                 -1 REVERSE_INULL defects
                +12 TAINTED_SCALAR defects

Reduced model (g_realloc never frees)             => 690 defects
                -12 NULL_RETURNS defects

Of course, silly me, I threw away the results of the analysis for the 
full model.  I'll now rerun it and look for false negatives caused by 
the reduced model.

Paolo