Frama-C-discuss mailing list archives

This page gathers the archives of the old Frama-C-discuss archives, that was hosted by Inria's gforge before its demise at the end of 2020. To search for mails newer than September 2020, please visit the page of the new mailing list on Renater.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Frama-c-discuss] Jessie - problem with an example

Hello Virgile,

it really solved the problem. Especially the indentation remark was a
helpful advice.
As indentation is not recognized but the mentioned ensures clause should be
valid for all behaviors I now placed it before the behavior clauses. 
 
Thank you,
Kerstin


> >     behavior yes:
> >       assumes data->a <= data->b + 10; 
> >       assigns data->b;
> >     ensures data->b <= data->a;
> >  */
> > void refresh(struct MyData* data)

> I guess your issue lies here: there is no post-condition saying that
> data->b is positive. We only know that it is less than or equal to
> data->a (By the way, your indentation is a bit misleading: the ensures
> relates only to the behavior 'yes', not to all behaviors).
> It is thus not possible to conclude that data->b is positive in the
> main loop after the call to refresh. Remember that function calls are
> seen as some kind of black box and that the only things which are known
> outside of the function body are the clauses of the contract.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/ms-tnef
Size: 3213 bytes
Desc: not available
Url : http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20090909/e048fd62/attachment.bin