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] question about a simple example and jessie

  • Subject: [Frama-c-discuss] question about a simple example and jessie
  • From: naghmeh.ghafari at (Naghmeh Ghafari)
  • Date: Mon, 03 May 2010 13:03:33 -0700


I am trying to verify a very simple bubble sort example, using jessie 
(Beryllium). My default solver is Alt-Ergo.  I used HAVOC (and Z3) to 
verify this example, which was relatively straight forward. I am using 
similar loop invariants, but  still there is a safety property 'variant 
decrease' that I can't verify. I think this is because of the 
While(true) loop I have for which I cannot come up with a proper 
strictly decreasing loop variant. I also cannot verify my post 
condition. I appreciate any suggestions or hint. In my version of 
jessie, I cannot  use  #pragma JessieTerminationPolicy (user). It is not 
recognized in my version.


#define TRUE 1
#define FALSE 0

/*@ requires size > 0;
   @  requires \valid(arr+ (0..size-1));
   @  ensures \forall int i; 0 <= i <= size - 2 ==> arr[i] <= arr[i+1];

void bubble_sort(int *arr, int size) {

   while (TRUE) {
     int aux = 0;
     int i = 0;

     /*@ loop invariant 0 <= i && i <= size -1 ;
       @          loop variant size - i;
     while (i < size-1) {
       if (arr[i] > arr[i+1]) {
           int tmp = arr[i];
           arr[i] = arr[i+1];
           arr[i+1] = tmp;
           aux = i;
    if (aux == 0) break;