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] Frama-C: Detecting unreachable code?


The following code has a useless if statement, which is always true, I was hoping to get some feedback on that issue, but all the behaviors are proved correct;

This code is a representative of a real error, which was manually detected during code review. I was trying to see whether WP can detect it...

[formal_verification]$ frama-c -wp -wp-rte always_true.c -lib-entry
[kernel] preprocessing with "gcc -C -E -I.  always_true.c"
[wp] Running WP plugin...
[wp] Collecting axiomatic usage
[rte] annotating function main
[wp] 4 goals scheduled
[wp] [Qed] Goal typed_main_complete_Low_High : Valid
[wp] [Qed] Goal typed_main_disjoint_Low_High : Valid
[wp] [Qed] Goal typed_main_High_post : Valid (4ms)
[wp] [Qed] Goal typed_main_Low_post : Valid

int MAX_VALUE = 100;

float x = 0.0;

int status = 0;

   requires MAX_VALUE == 100;

   behavior High:
    assumes x > MAX_VALUE;
    ensures status == -1;

   behavior Low:
     assumes x <= MAX_VALUE;
     ensures status == -1;

   complete behaviors;
   disjoint behaviors;

int main()

   if((x > MAX_VALUE) ||
      (x <= MAX_VALUE))
      status = -1;