def cegis(smt, params, k, r, statistics = {}):
global RESTART_THRESHOLD
print('===== CEGIS[k={0},r={1}] ====='.format(k,r))
### Initial values for statistics
statistics['time'] = 0
statistics['#smt_calls'] = 0
statistics['#restarts'] = 0
statistics['#parameter_candidates'] = 0
statistics['parameter_synthesis.time'] = []
statistics['parameter_synthesis.model'] = []
statistics['#counterexamples'] = 0
statistics['correctness_check.time'] = []
statistics['correctness_check.model'] = []
statistics['#randomizations'] = 0
statistics['counterexample_randomization.time'] = []
statistics['counterexample_randomization.model'] = []
total_time_start = time.time()
### Build correctness formula
init_smt = (smt + build_correctness_formula(k)).format(*params).split('\n')
### Remove parameters from SMT instance
prepared_smt = []
for line in init_smt:
matched = False
for p in params:
if line.strip().startswith('(define-fun ' + p):
a,b,c,d,e = line.split(' ')
prepared_smt.append('(declare-fun {0} {1} {2})'.format(b,c,d))
matched = True
if not matched:
prepared_smt.append(line)
init_smt = prepared_smt
count_no_progress = 0
while True:
### Restart the engine if CEGIS does not make progress
if r >= 3 and len(statistics['parameter_synthesis.model']) > 1:
total_progress = 0
for key in statistics['parameter_synthesis.model'][-2:][0]:
new_value = sexpr.str2sexpr(statistics['parameter_synthesis.model'][-2:][1][key])
# print(new_value)
if isinstance(new_value,list):
new_value = new_value[0]
new_value = eval_expression(new_value)
old_value = sexpr.str2sexpr(statistics['parameter_synthesis.model'][-2:][0][key])
# print(old_value)
if isinstance(old_value,list):
old_value = old_value[0]
old_value = eval_expression(old_value)
# print(new_value)
# print(old_value)
assert new_value[0] == True
assert old_value[0] == True
progress = new_value[1] - old_value[1]
total_progress += abs(progress)
if total_progress < 0.0000001:
print("N",end='')
count_no_progress += 1
if count_no_progress > 10:
print("R",end='')
count_no_progress = 0
statistics['#restarts'] += 1
check_smt = list(init_smt)
### Restart the engine (and forget all previously learned counterexamples)
if statistics['#counterexamples'] % RESTART_THRESHOLD == 0:
print("R",end='')
statistics['#restarts'] += 1
RESTART_THRESHOLD += 16*statistics['#restarts']
check_smt = list(init_smt)
else:
# print(statistics['#counterexamples'])
# print(RESTART_THRESHOLD)
# print(statistics['#counterexamples'] % RESTART_THRESHOLD == 0)
print('.',end='')
sys.stdout.flush()
### Compute parameters
compute_smt = list(check_smt)
statistics['#smt_calls'] += 1
statistics['#parameter_candidates'] += 1
ts = time.time()
(sat,model) = SMTsolve(compute_smt,params)
te = time.time()
statistics['parameter_synthesis.time'].append(te - ts)
statistics['parameter_synthesis.model'].append(model if sat else {})
if not sat:
total_time_end = time.time()
statistics['cegis.time'] = total_time_end - total_time_start
return False, {}
### Check k-correctness
correct_smt = []
for line in check_smt:
matched = False
for p in params:
if line.strip().startswith('(declare-fun ' + p):
a,b,c,d = line.split(' ')
correct_smt.append('(define-fun {0} {1} {2} {3})'.format(b,c,d[:-1],model[p]))
matched = True
if not matched:
correct_smt.append(line)
correct_smt.append('(declare-fun s0 () state)')
for i in range(0,k):
correct_smt.append('(declare-fun i{0} () input)'.format(i))
correct_smt.append('(assert (not (correct{0} s0 {1})))'
.format(k, ' '.join("i{0}".format(cnt) for cnt in range(0,k))))
statistics['#smt_calls'] += 1
statistics['#counterexamples'] += 1
ts = time.time()
(sat, cex) = SMTsolve(correct_smt, ['s0'] + ['i{0}'.format(j) for j in range(0,k)])
te = time.time()
statistics['correctness_check.time'].append(te - ts)
statistics['correctness_check.model'].append(cex if sat else {})
if not sat:
total_time_end = time.time()
statistics['cegis.time'] = total_time_end - total_time_start
return True, model
### Make counterexamples as nasty as possible
if r == 1 or (r >= 2 and statistics['#counterexamples'] % 2 == 0):
state = sexpr.str2sexpr(cex['s0'])[0][1:]
for i in range(0,len(state)):
try_state = []
for j in range(0,len(state)):
if i == j:
ok, value = randomize_if_necessary(state[i])
try_state.append(value)
else:
try_state.append(state[j])
state_sexpr = sexpr.str2sexpr(cex['s0'])[0]
state_sexpr[1:] = try_state
if state_sexpr == sexpr.str2sexpr(cex['s0'])[0]:
continue # skip the SMT check if no randomization happened
state_sexpr = sexpr.sexpr2str(state_sexpr)
nasty_check_smt = list(check_smt)
nasty_check_smt.append('(assert (not (correct{0} {1} {2})))'
.format(k, state_sexpr, " ".join([cex["i" + str(cnt)] for cnt in range(0,k)])))
statistics['#smt_calls'] += 1
statistics['#randomizations'] += 1
ts = time.time()
(sat, model) = SMTsolve(nasty_check_smt,params)
te = time.time()
statistics['counterexample_randomization.time'].append(te - ts)
statistics['counterexample_randomization.model'].append(cex if sat else {})
if sat:
# print("changed",state[i],"to",try_state[i])
state[i] = try_state[i]
state_sexpr = sexpr.str2sexpr(cex['s0'])[0]
state_sexpr[1:] = state
if cex['s0'] != sexpr.sexpr2str(state_sexpr):
print('G',end='')
cex['s0'] = sexpr.sexpr2str(state_sexpr)
### Make sure that the next parameters are better
check_smt.append('(assert (correct{0} {1} {2}))'.format(k, cex['s0'], " ".join([cex["i" + str(cnt)] for cnt in range(0,k)])))
def writeSExpr(self, list):
self.writeOut(sexpr.sexpr2str(list))
def cegis(smt, params, k, r, statistics={}):
global RESTART_THRESHOLD
print('===== CEGIS[k={0},r={1}] ====='.format(k, r))
### Initial values for statistics
statistics['time'] = 0
statistics['#smt_calls'] = 0
statistics['#restarts'] = 0
statistics['#parameter_candidates'] = 0
statistics['parameter_synthesis.time'] = []
statistics['parameter_synthesis.model'] = []
statistics['#counterexamples'] = 0
statistics['correctness_check.time'] = []
statistics['correctness_check.model'] = []
statistics['#randomizations'] = 0
statistics['counterexample_randomization.time'] = []
statistics['counterexample_randomization.model'] = []
total_time_start = time.time()
### Build correctness formula
init_smt = (smt + build_correctness_formula(k)).format(*params).split('\n')
### Remove parameters from SMT instance
prepared_smt = []
for line in init_smt:
matched = False
for p in params:
if line.strip().startswith('(define-fun ' + p):
a, b, c, d, e = line.split(' ')
prepared_smt.append('(declare-fun {0} {1} {2})'.format(
b, c, d))
matched = True
if not matched:
prepared_smt.append(line)
init_smt = prepared_smt
count_no_progress = 0
while True:
### Restart the engine if CEGIS does not make progress
if r >= 3 and len(statistics['parameter_synthesis.model']) > 1:
total_progress = 0
for key in statistics['parameter_synthesis.model'][-2:][0]:
new_value = sexpr.str2sexpr(
statistics['parameter_synthesis.model'][-2:][1][key])
# print(new_value)
if isinstance(new_value, list):
new_value = new_value[0]
new_value = eval_expression(new_value)
old_value = sexpr.str2sexpr(
statistics['parameter_synthesis.model'][-2:][0][key])
# print(old_value)
if isinstance(old_value, list):
old_value = old_value[0]
old_value = eval_expression(old_value)
# print(new_value)
# print(old_value)
assert new_value[0] == True
assert old_value[0] == True
progress = new_value[1] - old_value[1]
total_progress += abs(progress)
if total_progress < 0.0000001:
print("N", end='')
count_no_progress += 1
if count_no_progress > 10:
print("R", end='')
count_no_progress = 0
statistics['#restarts'] += 1
check_smt = list(init_smt)
### Restart the engine (and forget all previously learned counterexamples)
if statistics['#counterexamples'] % RESTART_THRESHOLD == 0:
print("R", end='')
statistics['#restarts'] += 1
RESTART_THRESHOLD += 16 * statistics['#restarts']
check_smt = list(init_smt)
else:
# print(statistics['#counterexamples'])
# print(RESTART_THRESHOLD)
# print(statistics['#counterexamples'] % RESTART_THRESHOLD == 0)
print('.', end='')
sys.stdout.flush()
### Compute parameters
compute_smt = list(check_smt)
statistics['#smt_calls'] += 1
statistics['#parameter_candidates'] += 1
ts = time.time()
(sat, model) = SMTsolve(compute_smt, params)
te = time.time()
statistics['parameter_synthesis.time'].append(te - ts)
statistics['parameter_synthesis.model'].append(model if sat else {})
if not sat:
total_time_end = time.time()
statistics['cegis.time'] = total_time_end - total_time_start
return False, {}
### Check k-correctness
correct_smt = []
for line in check_smt:
matched = False
for p in params:
if line.strip().startswith('(declare-fun ' + p):
a, b, c, d = line.split(' ')
correct_smt.append('(define-fun {0} {1} {2} {3})'.format(
b, c, d[:-1], model[p]))
matched = True
if not matched:
correct_smt.append(line)
correct_smt.append('(declare-fun s0 () state)')
for i in range(0, k):
correct_smt.append('(declare-fun i{0} () input)'.format(i))
correct_smt.append('(assert (not (correct{0} s0 {1})))'.format(
k, ' '.join("i{0}".format(cnt) for cnt in range(0, k))))
statistics['#smt_calls'] += 1
statistics['#counterexamples'] += 1
ts = time.time()
(sat, cex) = SMTsolve(correct_smt,
['s0'] + ['i{0}'.format(j) for j in range(0, k)])
te = time.time()
statistics['correctness_check.time'].append(te - ts)
statistics['correctness_check.model'].append(cex if sat else {})
if not sat:
total_time_end = time.time()
statistics['cegis.time'] = total_time_end - total_time_start
return True, model
### Make counterexamples as nasty as possible
if r == 1 or (r >= 2 and statistics['#counterexamples'] % 2 == 0):
state = sexpr.str2sexpr(cex['s0'])[0][1:]
for i in range(0, len(state)):
try_state = []
for j in range(0, len(state)):
if i == j:
ok, value = randomize_if_necessary(state[i])
try_state.append(value)
else:
try_state.append(state[j])
state_sexpr = sexpr.str2sexpr(cex['s0'])[0]
state_sexpr[1:] = try_state
if state_sexpr == sexpr.str2sexpr(cex['s0'])[0]:
continue # skip the SMT check if no randomization happened
state_sexpr = sexpr.sexpr2str(state_sexpr)
nasty_check_smt = list(check_smt)
nasty_check_smt.append(
'(assert (not (correct{0} {1} {2})))'.format(
k, state_sexpr,
" ".join([cex["i" + str(cnt)]
for cnt in range(0, k)])))
statistics['#smt_calls'] += 1
statistics['#randomizations'] += 1
ts = time.time()
(sat, model) = SMTsolve(nasty_check_smt, params)
te = time.time()
statistics['counterexample_randomization.time'].append(te - ts)
statistics['counterexample_randomization.model'].append(
cex if sat else {})
if sat:
# print("changed",state[i],"to",try_state[i])
state[i] = try_state[i]
state_sexpr = sexpr.str2sexpr(cex['s0'])[0]
state_sexpr[1:] = state
if cex['s0'] != sexpr.sexpr2str(state_sexpr):
print('G', end='')
cex['s0'] = sexpr.sexpr2str(state_sexpr)
### Make sure that the next parameters are better
check_smt.append('(assert (correct{0} {1} {2}))'.format(
k, cex['s0'],
" ".join([cex["i" + str(cnt)] for cnt in range(0, k)])))
