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[Frama-c-discuss] (no subject)

  • Subject: [Frama-c-discuss] (no subject)
  • From: gavran at mpi-sws.org (gavran at mpi-sws.org)
  • Date: Sat, 1 Nov 2014 21:02:40 +0100
  • In-reply-to: <DAE63505-C385-48D5-9045-9E5D0879415F@cea.fr>
  • References: <ddc718fd7d0e66a4f3e5121676cf59e2.squirrel@mail.mpi-sws.org> <DAE63505-C385-48D5-9045-9E5D0879415F@cea.fr>
Thanks for the answer. However, upon verifying it, I get
wp failure: Address of logic value (L_R).
Which plugin did you use to prove it?

Ivan

off question: what is prefered way communication? Should I continue
discussion on the mailing list or on Stack Overflow?

> The only way to handle your situation, is to make the result of new_value
> accessible from the logic space.
> For instance :
>
> //@ logic int * R ;
> //@ ensures \result == R && \valid(R) ; assigns \nothing ;
> extern int *new_value();
>
> //@ assigns *p;
> void f(int * p) { ? }
>
> //@ assigns *R ;
> int main(void) { ? }
>
> A more general solution would be to have a set if pointer for R, instead
> of a unique one.
> 	L.
>
> Le 31 oct. 2014 ? 16:09, gavran at mpi-sws.org a ?crit :
>
>> Hi,
>>
>> I have a problem with assigns clause. Assume the following code:
>>
>> /*@ ensures \result != \null;
>>  @ assigns \nothing;
>>  @*/
>> extern int *new_value();
>>
>> //@ assigns *p;
>> void f(int* p){
>>  *p = 8;
>> }
>> //@ assigns \nothing;
>> int main(void){
>> int *p = new_value();
>> f(p);
>> }
>>
>> The prover is unable to prove that main assigns \nothing, which makes
>> sense, as main assigns to *p through function f. However, how should I
>> state that in \assigns clause, since p is local variable and can not be
>> accessed within annotation?
>>
>> Ivan
>> p.s. I repeat the question posted on SO -
>> http://stackoverflow.com/questions/26591694/assigns-clause-for-local-variables-in-frama-c
>>
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>> Frama-c-discuss at lists.gforge.inria.fr
>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/frama-c-discuss
>
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