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add empty/full regular languages, escape sequence fixes, check cancellation inside simplifier

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2016-01-13 20:13:17 +01:00
parent 57e1d4dc1f
commit e0215400e2
5 changed files with 91 additions and 29 deletions
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28
src/ast/rewriter/seq_rewriter.cpp
View file

@ -126,14 +126,16 @@ eautomaton* re2automaton::re2aut(expr* e) {
}
return b.detach();
}
#if 0
else if (u.re.is_empty(e)) {
return alloc(eautomaton, m);
return alloc(eautomaton, sm);
}
else if (u.re.is_full(e)) {
sym_expr* _true = sym_expr::mk_pred(expr_ref(m.mk_true(), m));
return eautomaton::mk_loop(sm, _true);
}
#if 0
else if (u.re.is_intersect(e, e1, e2)) {
// maybe later
}
#endif
@ -1127,7 +1129,6 @@ bool seq_rewriter::reduce_eq(expr_ref_vector& ls, expr_ref_vector& rs, expr_ref_
if (set_empty(szr, _rs, true, lhs, rhs)) {
lchange |= szr > 1;
change |= szr > 1;
TRACE("seq", tout << lchange << " " << szr << "\n";);
if (szr == 1 && !lchange) {
lhs.reset();
rhs.reset();
@ -1322,23 +1323,20 @@ bool seq_rewriter::is_subsequence(unsigned szl, expr* const* l, unsigned szr, ex
for (unsigned i = 0; i < szl; ++i) {
bool found = false;
unsigned j = 0;
bool is_unit = m_util.str.is_unit(l[i]);
for (; !found && j < szr; ++j) {
found = !rpos.contains(j) && l[i] == r[j];
found = !rpos.contains(j) && (l[i] == r[j] || (is_unit && m_util.str.is_unit(r[j])));
}
if (!found) {
#if 0
std::cout << mk_pp(l[i], m()) << " not found in ";
for (unsigned j = 0; j < szr; ++j) {
std::cout << mk_pp(r[j], m()) << " ";
}
std::cout << "\n";
#endif
return false;
}
SASSERT(0 < j && j <= szr);
rpos.insert(j-1);
}
// if we reach here, then every element of l is contained in r in some position.
// or each non-unit in l is matched by a non-unit in r, and otherwise, the non-units match up.
bool change = false;
ptr_vector<expr> rs;
for (unsigned j = 0; j < szr; ++j) {
if (rpos.contains(j)) {
@ -1348,6 +1346,12 @@ bool seq_rewriter::is_subsequence(unsigned szl, expr* const* l, unsigned szr, ex
is_sat = false;
return true;
}
else {
change = true;
}
}
if (!change) {
return false;
}
SASSERT(szl == rs.size());
if (szl > 0) {

60
src/ast/seq_decl_plugin.cpp
View file

@ -36,18 +36,55 @@ static bool is_hex_digit(char ch, unsigned& d) {
static bool is_escape_char(char const *& s, unsigned& result) {
unsigned d1, d2;
if (*s == '\\' && *(s + 1) == 'x' &&
if (*s != '\\' || *(s + 1) == 0) {
return false;
}
if (*(s + 1) == 'x' &&
is_hex_digit(*(s + 2), d1) && is_hex_digit(*(s + 3), d2)) {
result = d1*16 + d2;
s += 4;
return true;
}
if (*s == '\\' && *(s + 1) == '\\') {
result = '\\';
switch (*(s + 1)) {
case 'a':
result = '\a';
s += 2;
return true;
case 'b':
result = '\b';
s += 2;
return true;
#if 0
case 'e':
result = '\e';
s += 2;
return true;
#endif
case 'f':
result = '\f';
s += 2;
return true;
case 'n':
result = '\n';
s += 2;
return true;
case 'r':
result = '\r';
s += 2;
return true;
case 't':
result = '\t';
s += 2;
return true;
case 'v':
result = '\v';
s += 2;
return true;
default:
result = *(s + 1);
s += 2;
return true;
}
return false;
}
zstring::zstring(encoding enc): m_encoding(enc) {}
@ -411,9 +448,9 @@ void seq_decl_plugin::init() {
m_sigs[OP_RE_UNION] = alloc(psig, m, "re.union", 1, 2, reAreA, reA);
m_sigs[OP_RE_INTERSECT] = alloc(psig, m, "re.inter", 1, 2, reAreA, reA);
m_sigs[OP_RE_LOOP] = alloc(psig, m, "re.loop", 1, 1, &reA, reA);
m_sigs[OP_RE_EMPTY_SET] = alloc(psig, m, "re-empty-set", 1, 0, 0, reA);
m_sigs[OP_RE_FULL_SET] = alloc(psig, m, "re-full-set", 1, 0, 0, reA);
m_sigs[OP_RE_OF_PRED] = alloc(psig, m, "re-of-pred", 1, 1, &predA, reA);
m_sigs[OP_RE_EMPTY_SET] = alloc(psig, m, "re.empty", 1, 0, 0, reA);
m_sigs[OP_RE_FULL_SET] = alloc(psig, m, "re.all", 1, 0, 0, reA);
m_sigs[OP_RE_OF_PRED] = alloc(psig, m, "re.of.pred", 1, 1, &predA, reA);
m_sigs[OP_SEQ_TO_RE] = alloc(psig, m, "seq.to.re", 1, 1, &seqA, reA);
m_sigs[OP_SEQ_IN_RE] = alloc(psig, m, "seq.in.re", 1, 2, seqAreA, boolT);
m_sigs[OP_STRING_CONST] = 0;
@ -429,6 +466,8 @@ void seq_decl_plugin::init() {
m_sigs[_OP_STRING_SUFFIX] = alloc(psig, m, "str.suffixof", 0, 2, str2T, boolT);
m_sigs[_OP_STRING_IN_REGEXP] = alloc(psig, m, "str.in.re", 0, 2, strTreT, boolT);
m_sigs[_OP_STRING_TO_REGEXP] = alloc(psig, m, "str.to.re", 0, 1, &strT, reT);
m_sigs[_OP_REGEXP_EMPTY] = alloc(psig, m, "re.nostr", 0, 0, 0, reT);
m_sigs[_OP_REGEXP_FULL] = alloc(psig, m, "re.allchar", 0, 0, 0, reT);
m_sigs[_OP_STRING_SUBSTR] = alloc(psig, m, "str.substr", 0, 3, strTint2T, strT);
}
@ -527,6 +566,13 @@ func_decl * seq_decl_plugin::mk_func_decl(decl_kind k, unsigned num_parameters,
match(*m_sigs[k], arity, domain, range, rng);
return m.mk_func_decl(m_sigs[k]->m_name, arity, domain, rng, func_decl_info(m_family_id, k));
case _OP_REGEXP_FULL:
match(*m_sigs[k], arity, domain, range, rng);
return m.mk_func_decl(symbol("re.allchar"), arity, domain, rng, func_decl_info(m_family_id, OP_RE_FULL_SET));
case _OP_REGEXP_EMPTY:
match(*m_sigs[k], arity, domain, range, rng);
return m.mk_func_decl(symbol("re.nostr"), arity, domain, rng, func_decl_info(m_family_id, OP_RE_EMPTY_SET));
case OP_RE_LOOP:
match(*m_sigs[k], arity, domain, range, rng);
if (num_parameters != 2 || !parameters[0].is_int() || !parameters[1].is_int()) {

4
src/ast/seq_decl_plugin.h
View file

@ -74,7 +74,9 @@ enum seq_op_kind {
_OP_STRING_TO_REGEXP,
_OP_STRING_CHARAT,
_OP_STRING_SUBSTR,
_OP_STRING_STRIDOF,
_OP_STRING_STRIDOF,
_OP_REGEXP_EMPTY,
_OP_REGEXP_FULL,
_OP_SEQ_SKOLEM,
LAST_SEQ_OP
};

10
src/ast/simplifier/simplifier.cpp
View file

@ -127,11 +127,11 @@ bool simplifier::get_subst(expr * n, expr_ref & r, proof_ref & p) {
return false;
}
void simplifier::reduce_core(expr * n) {
if (!is_cached(n)) {
void simplifier::reduce_core(expr * n1) {
if (!is_cached(n1)) {
// We do not assume m_todo is empty... So, we store the current size of the todo-stack.
unsigned sz = m_todo.size();
m_todo.push_back(n);
m_todo.push_back(n1);
while (m_todo.size() != sz) {
expr * n = m_todo.back();
if (is_cached(n))
@ -142,6 +142,10 @@ void simplifier::reduce_core(expr * n) {
m_todo.pop_back();
reduce1(n);
}
if (m.canceled()) {
cache_result(n1, n1, 0);
break;
}
}
}
}

18
src/smt/theory_seq.cpp
View file

@ -444,7 +444,9 @@ bool theory_seq::check_length_coherence(expr* e) {
propagate_is_conc(e, conc);
assume_equality(tail, emp);
}
m_trail_stack.push(push_replay(alloc(replay_length_coherence, m, e)));
if (!get_context().at_base_level()) {
m_trail_stack.push(push_replay(alloc(replay_length_coherence, m, e)));
}
return true;
}
return false;
@ -652,7 +654,7 @@ bool theory_seq::simplify_eq(expr_ref_vector& ls, expr_ref_vector& rs, dependenc
expr_ref_vector lhs(m), rhs(m);
bool changed = false;
if (!m_seq_rewrite.reduce_eq(ls, rs, lhs, rhs, changed)) {
// equality is inconsistent.x2
// equality is inconsistent.
TRACE("seq", tout << ls << " != " << rs << "\n";);
set_conflict(deps);
return true;
@ -1534,7 +1536,7 @@ void theory_seq::propagate() {
}
while (!m_replay.empty() && !ctx.inconsistent()) {
(*m_replay[m_replay.size()-1])(*this);
TRACE("seq", tout << "replay: " << ctx.get_scope_level() << "\n";);
TRACE("seq", tout << "replay at level: " << ctx.get_scope_level() << "\n";);
m_replay.pop_back();
}
if (m_new_solution) {
@ -1716,6 +1718,7 @@ void theory_seq::add_elim_string_axiom(expr* n) {
- len(x) >= 0 otherwise
*/
void theory_seq::add_length_axiom(expr* n) {
context& ctx = get_context();
expr* x;
VERIFY(m_util.str.is_length(n, x));
if (m_util.str.is_concat(x) ||
@ -1726,12 +1729,15 @@ void theory_seq::add_length_axiom(expr* n) {
m_rewrite(len);
SASSERT(n != len);
add_axiom(mk_eq(len, n, false));
m_trail_stack.push(push_replay(alloc(replay_axiom, m, n)));
if (!ctx.at_base_level()) {
m_trail_stack.push(push_replay(alloc(replay_axiom, m, n)));
}
}
else {
add_axiom(mk_literal(m_autil.mk_ge(n, m_autil.mk_int(0))));
m_trail_stack.push(push_replay(alloc(replay_axiom, m, n)));
if (!ctx.at_base_level()) {
m_trail_stack.push(push_replay(alloc(replay_axiom, m, n)));
}
}
}