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add theory_str::check_length_const_string

This commit is contained in:
Murphy Berzish 2016-07-28 16:31:40 -04:00
parent 95f1cfa5a6
commit 76ceac6664

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@ -4145,8 +4145,54 @@ bool theory_str::can_two_nodes_eq(expr * n1, expr * n2) {
// returns true if everything is OK, or false if inconsistency detected
// - note that these are different from the semantics in Z3str2
bool theory_str::check_length_const_string(expr * n1, expr * constStr) {
// TODO NEXT
NOT_IMPLEMENTED_YET(); return true;
ast_manager & mgr = get_manager();
context & ctx = get_context();
rational strLen((unsigned) (m_strutil.get_string_constant_value(constStr).length()));
if (is_concat(to_app(n1))) {
ptr_vector<expr> args;
expr_ref_vector items(mgr);
get_nodes_in_concat(n1, args);
rational sumLen(0);
for (unsigned int i = 0; i < args.size(); ++i) {
rational argLen;
bool argLen_exists = get_len_value(args[i], argLen);
if (argLen_exists) {
if (!m_strutil.is_string(args[i])) {
items.push_back(ctx.mk_eq_atom(mk_strlen(args[i]), mk_int(argLen)));
}
TRACE("t_str_detail", tout << "concat arg: " << mk_pp(args[i], mgr) << " has len = " << argLen.to_string() << std::endl;);
sumLen += argLen;
if (sumLen > strLen) {
items.push_back(ctx.mk_eq_atom(n1, constStr));
expr_ref toAssert(mgr.mk_not(mk_and(items)), mgr);
TRACE("t_str_detail", tout << "inconsistent length: concat (len = " << sumLen << ") <==> string constant (len = " << strLen << ")" << std::endl;);
assert_axiom(toAssert);
return false;
}
}
}
} else { // !is_concat(n1)
rational oLen;
bool oLen_exists = get_len_value(n1, oLen);
if (oLen_exists && oLen != strLen) {
TRACE("t_str_detail", tout << "inconsistent length: var (len = " << oLen << ") <==> string constant (len = " << strLen << ")" << std::endl;);
expr_ref l(ctx.mk_eq_atom(n1, constStr), mgr);
expr_ref r(ctx.mk_eq_atom(mk_strlen(n1), mk_strlen(constStr)), mgr);
assert_implication(l, r);
return false;
}
}
rational unused;
if (get_len_value(n1, unused) == false) {
expr_ref l(ctx.mk_eq_atom(n1, constStr), mgr);
expr_ref r(ctx.mk_eq_atom(mk_strlen(n1), mk_strlen(constStr)), mgr);
assert_implication(l, r);
}
return true;
}
// returns true if everything is OK, or false if inconsistency detected