gernst / korn Goto Github PK

Right now, Korn adds indices to the variables for the SMT Output.

Is it possible to add any delimiter-char (e.g. @ or anything else that is not/rarely used in variable names) to the variables?

(Right now it is hard / impossible to determine, if v15 is v1@5 or v@15)

In addition, there might be rare corner cases where this also causes issues with same variable names.

Building korn using make fails with

[chmod] korn.sh
~/tools/benchexec/contrib/plots/quantile-generator.py --correct test/2020-10-10.results/eld-summaries-900.2020-10-10_15-36-15.results.sv-comp20_prop-reachsafety.xml.bz2 > test/2020-10-10.results/eld-summaries-900.2020-10-10_15-36-15.csv
/bin/sh: 1: $HOME/tools/benchexec/contrib/plots/quantile-generator.py: not found
make: *** [Makefile:93: test/2020-10-10.results/eld-summaries-900.2020-10-10_15-36-15.csv] Error 127

Is this required or is this only for benchmarking?

I am using korn to only generate the CHCs for a svcomp-task.

Currently, Korn generates a new uninterpreted function (e.g. $main_if1) for a branch.
As far as i understood it, these predicates are summarizing the branch (similar to loop invariant).

As (at least in my use-case) each new predicate increases the complexity, it would be great to have an option to not generate these predicates but create two separate formulae (one if-branch and one -else branch), both continuing with the next statement

For this small example ex.c (as txt due to upload rules), which is

int main() {
  int i = 0;
  int j = 0;
  int l = 1;
  if(l==2){
    i = i + 1;
  }
  else {
    j = j+1;
  }
  
  assert((i+j) == l);
  return 0;
}

(which contains dead code in the if branch, i know)

It would be great if korn is able to generate two fomulae:

; if then  --> assert (= (+ i1 j2) l3)
(assert
     (=> (and (= l3 1)
             (= j2 0)
             (= i1 0)
             (= l3 2))
      (not (= (+ (+ i1 1) j2) l3))
        false))

; if else --> assert (= (+ i1 j2) l3)
((assert
     (=> (and (= l3 1)
             (= j2 0)
             (= i1 0)
             (not (= l3 2)))
      (not (= (+ i1 (+ j2 1)) l3))
        false))

This makes the verification process (at least in my usecase) easier.