1#!/usr/bin/env python
2
3"""
4Helper script to convert the log generated by '-debug-only=constraint-system'
5to a Python script that uses Z3 to verify the decisions using Z3's Python API.
6
7Example usage:
8
9> cat path/to/file.log
10---
11x6 + -1 * x7 <= -1
12x6 + -1 * x7 <= -2
13sat
14
15> ./convert-constraint-log-to-z3.py path/to/file.log > check.py && python ./check.py
16
17> cat check.py
18    from z3 import *
19x3 = Int("x3")
20x1 = Int("x1")
21x2 = Int("x2")
22s = Solver()
23s.add(x1 + -1 * x2 <= 0)
24s.add(x2 + -1 * x3 <= 0)
25s.add(-1 * x1 + x3 <= -1)
26assert(s.check() == unsat)
27print('all checks passed')
28"""
29
30
31import argparse
32import re
33
34
35def main():
36    parser = argparse.ArgumentParser(
37        description='Convert constraint log to script to verify using Z3.')
38    parser.add_argument('log_file', metavar='log', type=str,
39                        help='constraint-system log file')
40    args = parser.parse_args()
41
42    content = ''
43    with open(args.log_file, 'rt') as f:
44        content = f.read()
45
46    groups = content.split('---')
47    var_re = re.compile('x\d+')
48
49    print('from z3 import *')
50    for group in groups:
51        constraints = [g.strip() for g in group.split('\n') if g.strip() != '']
52        variables = set()
53        for c in constraints[:-1]:
54            for m in var_re.finditer(c):
55                variables.add(m.group())
56        if len(variables) == 0:
57            continue
58        for v in variables:
59            print('{} = Int("{}")'.format(v, v))
60        print('s = Solver()')
61        for c in constraints[:-1]:
62            print('s.add({})'.format(c))
63        expected = constraints[-1].strip()
64        print('assert(s.check() == {})'.format(expected))
65    print('print("all checks passed")')
66
67
68if __name__ == '__main__':
69    main()
70