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[Frama-c-discuss] [Jessie] Issue with behavior in contracts


David MENTRE wrote:
> Hello,
> 
> On Tue, Mar 3, 2009 at 17:30, David MENTRE <dmentre at linux-france.org> wrote:
>> I would like to define the behaviour of read() syscall. I'm using the
>> following contract:
>> /*@ requires fd >= 0;
>>    requires count > 0;
>>    requires \valid((char*)buf+(0..count-1));
>>    behavior error:
>>      assigns global_error_number;
>>      ensures \result < 0;
>>    behavior end_of_file:
>>      assigns \nothing;
>>      ensures \result == 0;
>>    behavior normal:
>>      assigns ((char*)buf)[0..count-1];
>>      ensures ((char*)buf)[0] >= 0 && ((char*)buf)[0] < 256;
>>      ensures \result > 0;
>>  */

Even worse: since you have no assumes clauses in your behaviors, then 
your specification says that at return, the \result is both < 0, == 0 
and >0. This is clearly wrong


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