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intersection WIP; fix polarity of generated path constraint LHS

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This commit is contained in:
Murphy Berzish 2018-01-15 14:08:15 -05:00
parent ca3784449f
commit 6f889ab699
1 changed files with 71 additions and 3 deletions
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74
src/smt/theory_str.cpp
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@ -6982,6 +6982,9 @@ namespace smt {
pathChars_len_constraints.push_back(ctx.mk_eq_atom(mk_strlen(ch), m_autil.mk_numeral(rational::one(), true)));
}
// TODO(mtrberzi) possibly modify this to reuse character terms over the same string,
// i.e. across different constraints over S the same variables S_0, S_1, ... are always used and refreshed
// modification of code in seq_rewriter::mk_str_in_regexp()
expr_ref_vector trail(m);
u_map<expr*> maps[2];
@ -9536,6 +9539,7 @@ namespace smt {
// regex automata
if (m_params.m_RegexAutomata) {
// TODO since heuristics might fail, the "no progress" flag might need to be handled specially here
// TODO learning of linear length constraints in the style of length automata, if possible?
bool regex_axiom_add = false;
for (obj_hashtable<expr>::iterator it = regex_terms.begin(); it != regex_terms.end(); ++it) {
expr * str_in_re = *it;
@ -9584,16 +9588,22 @@ namespace smt {
TRACE("str", tout << "character constraints are " << mk_pp(characterConstraints, m) << std::endl;);
expr_ref_vector lhs_terms(m);
lhs_terms.push_back(str_in_re);
if (current_assignment == l_true) {
lhs_terms.push_back(str_in_re);
} else {
lhs_terms.push_back(m.mk_not(str_in_re));
}
lhs_terms.push_back(ctx.mk_eq_atom(mk_strlen(str), m_autil.mk_numeral(exact_length_value, true)));
expr_ref lhs(mk_and(lhs_terms), m);
// If the automaton was built with the same polarity as the constraint,
// assert directly. Otherwise, negate the path constraint
if ( (current_assignment == l_true && assumption.get_polarity())
|| (current_assignment == l_false && !assumption.get_polarity())) {
TRACE("str", tout << "automaton and regex term have same polarity" << std::endl;);
expr_ref rhs(m.mk_and(pathConstraint, characterConstraints), m);
assert_implication(lhs, rhs);
} else {
TRACE("str", tout << "automaton and regex term have opposite polarity" << std::endl;);
expr_ref rhs(m.mk_and(m.mk_not(pathConstraint), characterConstraints), m);
assert_implication(lhs, rhs);
}
@ -9893,7 +9903,64 @@ namespace smt {
// choose an automaton/assumption for each assigned (str.in.re)
// that's consistent with the current length information
NOT_IMPLEMENTED_YET();
for (ptr_vector<expr>::iterator term_it = str_in_re_terms.begin();
term_it != str_in_re_terms.end(); ++term_it) {
expr * _unused;
expr * re;
SASSERT(u.str.is_in_re(*term_it));
u.str.is_in_re(*term_it, _unused, re);
rational exact_len;
bool has_exact_len = get_len_value(str, exact_len);
rational lb, ub;
bool has_lower_bound = lower_bound(mk_strlen(str), lb);
bool has_upper_bound = upper_bound(mk_strlen(str), ub);
if (regex_automaton_assumptions.contains(re) &&
!regex_automaton_assumptions[re].empty()){
for (svector<regex_automaton_under_assumptions>::iterator aut_it = regex_automaton_assumptions[re].begin();
aut_it != regex_automaton_assumptions[re].end(); ++aut_it) {
regex_automaton_under_assumptions aut = *aut_it;
rational aut_ub;
bool assume_ub = aut.get_upper_bound(aut_ub);
rational aut_lb;
bool assume_lb = aut.get_lower_bound(aut_lb);
bool consistent = true;
if (assume_ub) {
// check consistency of assumed upper bound
if (has_exact_len) {
if (exact_len > aut_ub) {
consistent = false;
}
} else {
if (has_upper_bound && ub > aut_ub) {
consistent = false;
}
}
}
if (assume_lb) {
// check consistency of assumed lower bound
if (has_exact_len) {
if (exact_len < aut_lb) {
consistent = false;
}
} else {
if (has_lower_bound && lb < aut_lb) {
consistent = false;
}
}
}
if (consistent) {
intersect_constraints.push_back(aut);
break;
}
}
}
} // foreach(term in str_in_re_terms)
eautomaton * aut_inter = NULL;
CTRACE("str", !intersect_constraints.empty(), tout << "check intersection of automata constraints for " << mk_pp(str, m) << std::endl;);
@ -9933,7 +10000,8 @@ namespace smt {
}
}
} // foreach(entry in intersect_constraints)
if (aut_inter->is_empty()) {
TRACE("str", tout << "intersected " << used_intersect_constraints.size() << " constraints" << std::endl;);
if (aut_inter != NULL && aut_inter->is_empty()) {
TRACE("str", tout << "product automaton is empty; asserting conflict clause" << std::endl;);
NOT_IMPLEMENTED_YET();
}