On Thu, 1 Jul 2010, Lucas De Marchi wrote:
> On Thu, Jul 1, 2010 at 2:28 AM, Julia Lawall <[email protected]> wrote:
> > It should also be possible to do this using T1 multiple times. For
> > example, for the declaration case, you could write:
> >
> > @r@
> > type T1,T2;
> > identifier c;
> > position p;
> > @@
> >
> > (
> > T1 *c = calloc(sizeof(T1),...);
> this one is a correct declaration.
That was intentional. The position variable is not bound in this case.
With this case, the case below should only match when T1 and T2 are
different. You can do a similar thing for the *b case.
> > |
> > T1 *...@p = calloc(sizeof(T2),...);
> > )
> >
> > You can of course extend it to take into account the other cases you have
> > considered.
>
> I think you intended to use this one:
> (
> T1 *...@p = calloc(sizeof(*b), ...);
> |
> T1 *...@p = calloc(sizeof(T2), ...);
> )
>
> This doesn't work neither. It says this declaration is wrong, which is
> obviously not:
>
> struct b *b = calloc(sizeof(*b), 1);
>
> For the file attached previously and removing the "if t1 != t2" in
> python, it prints:
>
> WARNING: wrong size to calloc function => test-coccinelle-wrong-alloc.c:18
> Type is 'struct b', but 'sizeof(struct b)' was allocated
> WARNING: wrong size to calloc function => test-coccinelle-wrong-alloc.c:19
> Type is 'struct a', but 'sizeof(struct b)' was allocated
>
> >
> > For Linux, I made the following rule, which finds problems when the size
> > computation is more complicated:
> >
> > @r@
> > type T;
> > T *x;
> > position p;
> > @@
> >
> > x...@p = <+...sizeof(T)...+>
> >
> > @s@
> > expression x;
> > position p;
> > @@
> >
> > x...@p = <+...sizeof(*x)...+>
> >
> > @bad@
> > position p!={r.p,s.p};
>
> Ahn... ok, this is indeed better than what I did. Write rules for the
> good cases and another one for the bad ones, right?
Yes, that is one often useful strategy.
julia
> > type T, T1, T2;
> > T1 *x;
> > T2 **y;
> > typedef u8;
> > {void *, char *, unsigned char *, u8*} a;
> > {struct device,struct net_device} dev;
> > @@
> >
> > (
> > y = \(kmalloc\|kzalloc\)(<+...sizeof(T)...+>,...)
> > |
> > a = \(kmalloc\|kzalloc\)(<+...sizeof(T)...+>,...)
> > |
> > x...@p = \(kmalloc\|kzalloc\)(<+...sizeof(T)...+>,...)
> > )
>
>
> Lucas De Marchi
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