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z3/src/smt/theory_str.cpp
Nikolaj Bjorner d8c3b273d3 adding benign initialization 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
2017-05-08 10:50:06 -07:00

10575 lines
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/*++
Module Name:
theory_str.cpp
Abstract:
String Theory Plugin
Author:
Murphy Berzish and Yunhui Zheng
Revision History:
--*/
#include"ast_smt2_pp.h"
#include"smt_context.h"
#include"theory_str.h"
#include"smt_model_generator.h"
#include"ast_pp.h"
#include"ast_ll_pp.h"
#include<list>
#include<vector>
#include<algorithm>
#include"theory_seq_empty.h"
#include"theory_arith.h"
namespace smt {
theory_str::theory_str(ast_manager & m, theory_str_params const & params):
theory(m.mk_family_id("seq")),
m_params(params),
/* Options */
opt_EagerStringConstantLengthAssertions(true),
opt_VerifyFinalCheckProgress(true),
opt_LCMUnrollStep(2),
opt_NoQuickReturn_IntegerTheory(false),
opt_DisableIntegerTheoryIntegration(false),
opt_DeferEQCConsistencyCheck(false),
opt_CheckVariableScope(true),
opt_ConcatOverlapAvoid(true),
/* Internal setup */
search_started(false),
m_autil(m),
u(m),
sLevel(0),
finalCheckProgressIndicator(false),
m_trail(m),
m_delayed_axiom_setup_terms(m),
tmpStringVarCount(0),
tmpXorVarCount(0),
tmpLenTestVarCount(0),
tmpValTestVarCount(0),
avoidLoopCut(true),
loopDetected(false),
m_theoryStrOverlapAssumption_term(m),
contains_map(m),
string_int_conversion_terms(m),
totalCacheAccessCount(0),
cacheHitCount(0),
cacheMissCount(0),
m_find(*this),
m_trail_stack(*this)
{
initialize_charset();
}
theory_str::~theory_str() {
m_trail_stack.reset();
}
expr * theory_str::mk_string(zstring const& str) {
if (m_params.m_StringConstantCache) {
++totalCacheAccessCount;
expr * val;
if (stringConstantCache.find(str, val)) {
return val;
} else {
val = u.str.mk_string(str);
m_trail.push_back(val);
stringConstantCache.insert(str, val);
return val;
}
} else {
return u.str.mk_string(str);
}
}
expr * theory_str::mk_string(const char * str) {
symbol sym(str);
return u.str.mk_string(sym);
}
void theory_str::initialize_charset() {
bool defaultCharset = true;
if (defaultCharset) {
// valid C strings can't contain the null byte ('\0')
charSetSize = 255;
char_set = alloc_svect(char, charSetSize);
int idx = 0;
// small letters
for (int i = 97; i < 123; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
// caps
for (int i = 65; i < 91; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
// numbers
for (int i = 48; i < 58; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
// printable marks - 1
for (int i = 32; i < 48; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
// printable marks - 2
for (int i = 58; i < 65; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
// printable marks - 3
for (int i = 91; i < 97; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
// printable marks - 4
for (int i = 123; i < 127; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
// non-printable - 1
for (int i = 1; i < 32; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
// non-printable - 2
for (int i = 127; i < 256; i++) {
char_set[idx] = (char) i;
charSetLookupTable[char_set[idx]] = idx;
idx++;
}
} else {
const char setset[] = { 'a', 'b', 'c' };
int fSize = sizeof(setset) / sizeof(char);
char_set = alloc_svect(char, fSize);
charSetSize = fSize;
for (int i = 0; i < charSetSize; i++) {
char_set[i] = setset[i];
charSetLookupTable[setset[i]] = i;
}
}
}
void theory_str::assert_axiom(expr * e) {
if (opt_VerifyFinalCheckProgress) {
finalCheckProgressIndicator = true;
}
if (get_manager().is_true(e)) return;
TRACE("str", tout << "asserting " << mk_ismt2_pp(e, get_manager()) << std::endl;);
context & ctx = get_context();
if (!ctx.b_internalized(e)) {
ctx.internalize(e, false);
}
literal lit(ctx.get_literal(e));
ctx.mark_as_relevant(lit);
ctx.mk_th_axiom(get_id(), 1, &lit);
// crash/error avoidance: add all axioms to the trail
m_trail.push_back(e);
//TRACE("str", tout << "done asserting " << mk_ismt2_pp(e, get_manager()) << std::endl;);
}
expr * theory_str::rewrite_implication(expr * premise, expr * conclusion) {
ast_manager & m = get_manager();
return m.mk_or(m.mk_not(premise), conclusion);
}
void theory_str::assert_implication(expr * premise, expr * conclusion) {
ast_manager & m = get_manager();
TRACE("str", tout << "asserting implication " << mk_ismt2_pp(premise, m) << " -> " << mk_ismt2_pp(conclusion, m) << std::endl;);
expr_ref axiom(m.mk_or(m.mk_not(premise), conclusion), m);
assert_axiom(axiom);
}
bool theory_str::internalize_atom(app * atom, bool gate_ctx) {
return internalize_term(atom);
}
bool theory_str::internalize_term(app * term) {
context & ctx = get_context();
ast_manager & m = get_manager();
SASSERT(term->get_family_id() == get_family_id());
TRACE("str", tout << "internalizing term: " << mk_ismt2_pp(term, get_manager()) << std::endl;);
// emulation of user_smt_theory::internalize_term()
unsigned num_args = term->get_num_args();
for (unsigned i = 0; i < num_args; ++i) {
ctx.internalize(term->get_arg(i), false);
}
if (ctx.e_internalized(term)) {
enode * e = ctx.get_enode(term);
mk_var(e);
return true;
}
// m_parents.push_back(term);
enode * e = ctx.mk_enode(term, false, m.is_bool(term), true);
if (m.is_bool(term)) {
bool_var bv = ctx.mk_bool_var(term);
ctx.set_var_theory(bv, get_id());
ctx.set_enode_flag(bv, true);
}
// make sure every argument is attached to a theory variable
for (unsigned i = 0; i < num_args; ++i) {
enode * arg = e->get_arg(i);
theory_var v_arg = mk_var(arg);
TRACE("str", tout << "arg has theory var #" << v_arg << std::endl;);
}
theory_var v = mk_var(e);
TRACE("str", tout << "term has theory var #" << v << std::endl;);
if (opt_EagerStringConstantLengthAssertions && u.str.is_string(term)) {
TRACE("str", tout << "eagerly asserting length of string term " << mk_pp(term, m) << std::endl;);
m_basicstr_axiom_todo.insert(e);
}
return true;
}
enode* theory_str::ensure_enode(expr* e) {
context& ctx = get_context();
if (!ctx.e_internalized(e)) {
ctx.internalize(e, false);
}
enode* n = ctx.get_enode(e);
ctx.mark_as_relevant(n);
return n;
}
void theory_str::refresh_theory_var(expr * e) {
enode * en = ensure_enode(e);
theory_var v = mk_var(en);
TRACE("str", tout << "refresh " << mk_pp(e, get_manager()) << ": v#" << v << std::endl;);
m_basicstr_axiom_todo.push_back(en);
}
theory_var theory_str::mk_var(enode* n) {
TRACE("str", tout << "mk_var for " << mk_pp(n->get_owner(), get_manager()) << std::endl;);
ast_manager & m = get_manager();
if (!(m.get_sort(n->get_owner()) == u.str.mk_string_sort())) {
return null_theory_var;
}
if (is_attached_to_var(n)) {
TRACE("str", tout << "already attached to theory var" << std::endl;);
return n->get_th_var(get_id());
} else {
theory_var v = theory::mk_var(n);
m_find.mk_var();
TRACE("str", tout << "new theory var v#" << v << std::endl;);
get_context().attach_th_var(n, this, v);
get_context().mark_as_relevant(n);
return v;
}
}
static void cut_vars_map_copy(std::map<expr*, int> & dest, std::map<expr*, int> & src) {
std::map<expr*, int>::iterator itor = src.begin();
for (; itor != src.end(); itor++) {
dest[itor->first] = 1;
}
}
bool theory_str::has_self_cut(expr * n1, expr * n2) {
if (!cut_var_map.contains(n1)) {
return false;
}
if (!cut_var_map.contains(n2)) {
return false;
}
if (cut_var_map[n1].empty() || cut_var_map[n2].empty()) {
return false;
}
std::map<expr*, int>::iterator itor = cut_var_map[n1].top()->vars.begin();
for (; itor != cut_var_map[n1].top()->vars.end(); ++itor) {
if (cut_var_map[n2].top()->vars.find(itor->first) != cut_var_map[n2].top()->vars.end()) {
return true;
}
}
return false;
}
void theory_str::add_cut_info_one_node(expr * baseNode, int slevel, expr * node) {
// crash avoidance?
m_trail.push_back(baseNode);
m_trail.push_back(node);
if (!cut_var_map.contains(baseNode)) {
T_cut * varInfo = alloc(T_cut);
varInfo->level = slevel;
varInfo->vars[node] = 1;
cut_var_map.insert(baseNode, std::stack<T_cut*>());
cut_var_map[baseNode].push(varInfo);
TRACE("str", tout << "add var info for baseNode=" << mk_pp(baseNode, get_manager()) << ", node=" << mk_pp(node, get_manager()) << " [" << slevel << "]" << std::endl;);
} else {
if (cut_var_map[baseNode].empty()) {
T_cut * varInfo = alloc(T_cut);
varInfo->level = slevel;
varInfo->vars[node] = 1;
cut_var_map[baseNode].push(varInfo);
TRACE("str", tout << "add var info for baseNode=" << mk_pp(baseNode, get_manager()) << ", node=" << mk_pp(node, get_manager()) << " [" << slevel << "]" << std::endl;);
} else {
if (cut_var_map[baseNode].top()->level < slevel) {
T_cut * varInfo = alloc(T_cut);
varInfo->level = slevel;
cut_vars_map_copy(varInfo->vars, cut_var_map[baseNode].top()->vars);
varInfo->vars[node] = 1;
cut_var_map[baseNode].push(varInfo);
TRACE("str", tout << "add var info for baseNode=" << mk_pp(baseNode, get_manager()) << ", node=" << mk_pp(node, get_manager()) << " [" << slevel << "]" << std::endl;);
} else if (cut_var_map[baseNode].top()->level == slevel) {
cut_var_map[baseNode].top()->vars[node] = 1;
TRACE("str", tout << "add var info for baseNode=" << mk_pp(baseNode, get_manager()) << ", node=" << mk_pp(node, get_manager()) << " [" << slevel << "]" << std::endl;);
} else {
get_manager().raise_exception("entered illegal state during add_cut_info_one_node()");
}
}
}
}
void theory_str::add_cut_info_merge(expr * destNode, int slevel, expr * srcNode) {
// crash avoidance?
m_trail.push_back(destNode);
m_trail.push_back(srcNode);
if (!cut_var_map.contains(srcNode)) {
get_manager().raise_exception("illegal state in add_cut_info_merge(): cut_var_map doesn't contain srcNode");
}
if (cut_var_map[srcNode].empty()) {
get_manager().raise_exception("illegal state in add_cut_info_merge(): cut_var_map[srcNode] is empty");
}
if (!cut_var_map.contains(destNode)) {
T_cut * varInfo = alloc(T_cut);
varInfo->level = slevel;
cut_vars_map_copy(varInfo->vars, cut_var_map[srcNode].top()->vars);
cut_var_map.insert(destNode, std::stack<T_cut*>());
cut_var_map[destNode].push(varInfo);
TRACE("str", tout << "merge var info for destNode=" << mk_pp(destNode, get_manager()) << ", srcNode=" << mk_pp(srcNode, get_manager()) << " [" << slevel << "]" << std::endl;);
} else {
if (cut_var_map[destNode].empty() || cut_var_map[destNode].top()->level < slevel) {
T_cut * varInfo = alloc(T_cut);
varInfo->level = slevel;
cut_vars_map_copy(varInfo->vars, cut_var_map[destNode].top()->vars);
cut_vars_map_copy(varInfo->vars, cut_var_map[srcNode].top()->vars);
cut_var_map[destNode].push(varInfo);
TRACE("str", tout << "merge var info for destNode=" << mk_pp(destNode, get_manager()) << ", srcNode=" << mk_pp(srcNode, get_manager()) << " [" << slevel << "]" << std::endl;);
} else if (cut_var_map[destNode].top()->level == slevel) {
cut_vars_map_copy(cut_var_map[destNode].top()->vars, cut_var_map[srcNode].top()->vars);
TRACE("str", tout << "merge var info for destNode=" << mk_pp(destNode, get_manager()) << ", srcNode=" << mk_pp(srcNode, get_manager()) << " [" << slevel << "]" << std::endl;);
} else {
get_manager().raise_exception("illegal state in add_cut_info_merge(): inconsistent slevels");
}
}
}
void theory_str::check_and_init_cut_var(expr * node) {
if (cut_var_map.contains(node)) {
return;
} else if (!u.str.is_string(node)) {
add_cut_info_one_node(node, -1, node);
}
}
literal theory_str::mk_literal(expr* _e) {
ast_manager & m = get_manager();
expr_ref e(_e, m);
context& ctx = get_context();
ensure_enode(e);
return ctx.get_literal(e);
}
app * theory_str::mk_int(int n) {
return m_autil.mk_numeral(rational(n), true);
}
app * theory_str::mk_int(rational & q) {
return m_autil.mk_numeral(q, true);
}
expr * theory_str::mk_internal_lenTest_var(expr * node, int lTries) {
ast_manager & m = get_manager();
std::stringstream ss;
ss << "$$_len_" << mk_ismt2_pp(node, m) << "_" << lTries << "_" << tmpLenTestVarCount;
tmpLenTestVarCount += 1;
std::string name = ss.str();
app * var = mk_str_var(name);
internal_lenTest_vars.insert(var);
m_trail.push_back(var);
return var;
}
expr * theory_str::mk_internal_valTest_var(expr * node, int len, int vTries) {
ast_manager & m = get_manager();
std::stringstream ss;
ss << "$$_val_" << mk_ismt2_pp(node, m) << "_" << len << "_" << vTries << "_" << tmpValTestVarCount;
tmpValTestVarCount += 1;
std::string name = ss.str();
app * var = mk_str_var(name);
internal_valTest_vars.insert(var);
m_trail.push_back(var);
return var;
}
void theory_str::track_variable_scope(expr * var) {
if (internal_variable_scope_levels.find(sLevel) == internal_variable_scope_levels.end()) {
internal_variable_scope_levels[sLevel] = std::set<expr*>();
}
internal_variable_scope_levels[sLevel].insert(var);
}
app * theory_str::mk_internal_xor_var() {
return mk_int_var("$$_xor");
}
app * theory_str::mk_fresh_const(char const* name, sort* s) {
return u.mk_skolem(symbol(name), 0, 0, s);
}
app * theory_str::mk_int_var(std::string name) {
context & ctx = get_context();
ast_manager & m = get_manager();
TRACE("str", tout << "creating integer variable " << name << " at scope level " << sLevel << std::endl;);
sort * int_sort = m.mk_sort(m_autil.get_family_id(), INT_SORT);
app * a = mk_fresh_const(name.c_str(), int_sort);
ctx.internalize(a, false);
SASSERT(ctx.get_enode(a) != NULL);
SASSERT(ctx.e_internalized(a));
ctx.mark_as_relevant(a);
// I'm assuming that this combination will do the correct thing in the integer theory.
//mk_var(ctx.get_enode(a));
m_trail.push_back(a);
//variable_set.insert(a);
//internal_variable_set.insert(a);
//track_variable_scope(a);
return a;
}
app * theory_str::mk_unroll_bound_var() {
return mk_int_var("unroll");
}
app * theory_str::mk_unroll_test_var() {
app * v = mk_str_var("unrollTest"); // was uRt
internal_unrollTest_vars.insert(v);
track_variable_scope(v);
return v;
}
app * theory_str::mk_str_var(std::string name) {
context & ctx = get_context();
ast_manager & m = get_manager();
TRACE("str", tout << "creating string variable " << name << " at scope level " << sLevel << std::endl;);
sort * string_sort = u.str.mk_string_sort();
app * a = mk_fresh_const(name.c_str(), string_sort);
TRACE("str", tout << "a->get_family_id() = " << a->get_family_id() << std::endl
<< "this->get_family_id() = " << this->get_family_id() << std::endl;);
// I have a hunch that this may not get internalized for free...
ctx.internalize(a, false);
SASSERT(ctx.get_enode(a) != NULL);
SASSERT(ctx.e_internalized(a));
// this might help??
mk_var(ctx.get_enode(a));
m_basicstr_axiom_todo.push_back(ctx.get_enode(a));
TRACE("str", tout << "add " << mk_pp(a, m) << " to m_basicstr_axiom_todo" << std::endl;);
m_trail.push_back(a);
variable_set.insert(a);
internal_variable_set.insert(a);
track_variable_scope(a);
return a;
}
app * theory_str::mk_regex_rep_var() {
context & ctx = get_context();
ast_manager & m = get_manager();
sort * string_sort = u.str.mk_string_sort();
app * a = mk_fresh_const("regex", string_sort);
ctx.internalize(a, false);
SASSERT(ctx.get_enode(a) != NULL);
SASSERT(ctx.e_internalized(a));
mk_var(ctx.get_enode(a));
m_basicstr_axiom_todo.push_back(ctx.get_enode(a));
TRACE("str", tout << "add " << mk_pp(a, m) << " to m_basicstr_axiom_todo" << std::endl;);
m_trail.push_back(a);
variable_set.insert(a);
//internal_variable_set.insert(a);
regex_variable_set.insert(a);
track_variable_scope(a);
return a;
}
void theory_str::add_nonempty_constraint(expr * s) {
context & ctx = get_context();
ast_manager & m = get_manager();
expr_ref ax1(m.mk_not(ctx.mk_eq_atom(s, mk_string(""))), m);
assert_axiom(ax1);
{
// build LHS
expr_ref len_str(mk_strlen(s), m);
SASSERT(len_str);
// build RHS
expr_ref zero(m_autil.mk_numeral(rational(0), true), m);
SASSERT(zero);
// build LHS > RHS and assert
// we have to build !(LHS <= RHS) instead
expr_ref lhs_gt_rhs(m.mk_not(m_autil.mk_le(len_str, zero)), m);
SASSERT(lhs_gt_rhs);
assert_axiom(lhs_gt_rhs);
}
}
app * theory_str::mk_nonempty_str_var() {
context & ctx = get_context();
ast_manager & m = get_manager();
std::stringstream ss;
ss << tmpStringVarCount;
tmpStringVarCount++;
std::string name = "$$_str" + ss.str();
TRACE("str", tout << "creating nonempty string variable " << name << " at scope level " << sLevel << std::endl;);
sort * string_sort = u.str.mk_string_sort();
app * a = mk_fresh_const(name.c_str(), string_sort);
ctx.internalize(a, false);
SASSERT(ctx.get_enode(a) != NULL);
// this might help??
mk_var(ctx.get_enode(a));
// assert a variation of the basic string axioms that ensures this string is nonempty
{
// build LHS
expr_ref len_str(mk_strlen(a), m);
SASSERT(len_str);
// build RHS
expr_ref zero(m_autil.mk_numeral(rational(0), true), m);
SASSERT(zero);
// build LHS > RHS and assert
// we have to build !(LHS <= RHS) instead
expr_ref lhs_gt_rhs(m.mk_not(m_autil.mk_le(len_str, zero)), m);
SASSERT(lhs_gt_rhs);
assert_axiom(lhs_gt_rhs);
}
// add 'a' to variable sets, so we can keep track of it
m_trail.push_back(a);
variable_set.insert(a);
internal_variable_set.insert(a);
track_variable_scope(a);
return a;
}
app * theory_str::mk_unroll(expr * n, expr * bound) {
context & ctx = get_context();
ast_manager & m = get_manager();
expr * args[2] = {n, bound};
app * unrollFunc = get_manager().mk_app(get_id(), _OP_RE_UNROLL, 0, 0, 2, args);
m_trail.push_back(unrollFunc);
expr_ref_vector items(m);
items.push_back(ctx.mk_eq_atom(ctx.mk_eq_atom(bound, mk_int(0)), ctx.mk_eq_atom(unrollFunc, mk_string(""))));
items.push_back(m_autil.mk_ge(bound, mk_int(0)));
items.push_back(m_autil.mk_ge(mk_strlen(unrollFunc), mk_int(0)));
expr_ref finalAxiom(mk_and(items), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
return unrollFunc;
}
app * theory_str::mk_contains(expr * haystack, expr * needle) {
app * contains = u.str.mk_contains(haystack, needle); // TODO double-check semantics/argument order
m_trail.push_back(contains);
// immediately force internalization so that axiom setup does not fail
get_context().internalize(contains, false);
set_up_axioms(contains);
return contains;
}
app * theory_str::mk_indexof(expr * haystack, expr * needle) {
// TODO check meaning of the third argument here
app * indexof = u.str.mk_index(haystack, needle, mk_int(0));
m_trail.push_back(indexof);
// immediately force internalization so that axiom setup does not fail
get_context().internalize(indexof, false);
set_up_axioms(indexof);
return indexof;
}
app * theory_str::mk_strlen(expr * e) {
/*if (m_strutil.is_string(e)) {*/ if (false) {
zstring strval;
u.str.is_string(e, strval);
unsigned int len = strval.length();
return m_autil.mk_numeral(rational(len), true);
} else {
if (false) {
// use cache
app * lenTerm = NULL;
if (!length_ast_map.find(e, lenTerm)) {
lenTerm = u.str.mk_length(e);
length_ast_map.insert(e, lenTerm);
m_trail.push_back(lenTerm);
}
return lenTerm;
} else {
// always regen
return u.str.mk_length(e);
}
}
}
/*
* Returns the simplified concatenation of two expressions,
* where either both expressions are constant strings
* or one expression is the empty string.
* If this precondition does not hold, the function returns NULL.
* (note: this function was strTheory::Concat())
*/
expr * theory_str::mk_concat_const_str(expr * n1, expr * n2) {
bool n1HasEqcValue = false;
bool n2HasEqcValue = false;
expr * v1 = get_eqc_value(n1, n1HasEqcValue);
expr * v2 = get_eqc_value(n2, n2HasEqcValue);
if (n1HasEqcValue && n2HasEqcValue) {
zstring n1_str;
u.str.is_string(v1, n1_str);
zstring n2_str;
u.str.is_string(v2, n2_str);
zstring result = n1_str + n2_str;
return mk_string(result);
} else if (n1HasEqcValue && !n2HasEqcValue) {
zstring n1_str;
u.str.is_string(v1, n1_str);
if (n1_str.empty()) {
return n2;
}
} else if (!n1HasEqcValue && n2HasEqcValue) {
zstring n2_str;
u.str.is_string(v2, n2_str);
if (n2_str.empty()) {
return n1;
}
}
return NULL;
}
expr * theory_str::mk_concat(expr * n1, expr * n2) {
context & ctx = get_context();
ast_manager & m = get_manager();
ENSURE(n1 != NULL);
ENSURE(n2 != NULL);
bool n1HasEqcValue = false;
bool n2HasEqcValue = false;
n1 = get_eqc_value(n1, n1HasEqcValue);
n2 = get_eqc_value(n2, n2HasEqcValue);
if (n1HasEqcValue && n2HasEqcValue) {
return mk_concat_const_str(n1, n2);
} else if (n1HasEqcValue && !n2HasEqcValue) {
bool n2_isConcatFunc = u.str.is_concat(to_app(n2));
zstring n1_str;
u.str.is_string(n1, n1_str);
if (n1_str.empty()) {
return n2;
}
if (n2_isConcatFunc) {
expr * n2_arg0 = to_app(n2)->get_arg(0);
expr * n2_arg1 = to_app(n2)->get_arg(1);
if (u.str.is_string(n2_arg0)) {
n1 = mk_concat_const_str(n1, n2_arg0); // n1 will be a constant
n2 = n2_arg1;
}
}
} else if (!n1HasEqcValue && n2HasEqcValue) {
zstring n2_str;
u.str.is_string(n2, n2_str);
if (n2_str.empty()) {
return n1;
}
if (u.str.is_concat(to_app(n1))) {
expr * n1_arg0 = to_app(n1)->get_arg(0);
expr * n1_arg1 = to_app(n1)->get_arg(1);
if (u.str.is_string(n1_arg1)) {
n1 = n1_arg0;
n2 = mk_concat_const_str(n1_arg1, n2); // n2 will be a constant
}
}
} else {
if (u.str.is_concat(to_app(n1)) && u.str.is_concat(to_app(n2))) {
expr * n1_arg0 = to_app(n1)->get_arg(0);
expr * n1_arg1 = to_app(n1)->get_arg(1);
expr * n2_arg0 = to_app(n2)->get_arg(0);
expr * n2_arg1 = to_app(n2)->get_arg(1);
if (u.str.is_string(n1_arg1) && u.str.is_string(n2_arg0)) {
expr * tmpN1 = n1_arg0;
expr * tmpN2 = mk_concat_const_str(n1_arg1, n2_arg0);
n1 = mk_concat(tmpN1, tmpN2);
n2 = n2_arg1;
}
}
}
//------------------------------------------------------
// * expr * ast1 = mk_2_arg_app(ctx, td->Concat, n1, n2);
// * expr * ast2 = mk_2_arg_app(ctx, td->Concat, n1, n2);
// Z3 treats (ast1) and (ast2) as two different nodes.
//-------------------------------------------------------
expr * concatAst = NULL;
if (!concat_astNode_map.find(n1, n2, concatAst)) {
concatAst = u.str.mk_concat(n1, n2);
m_trail.push_back(concatAst);
concat_astNode_map.insert(n1, n2, concatAst);
expr_ref concat_length(mk_strlen(concatAst), m);
ptr_vector<expr> childrenVector;
get_nodes_in_concat(concatAst, childrenVector);
expr_ref_vector items(m);
for (unsigned int i = 0; i < childrenVector.size(); i++) {
items.push_back(mk_strlen(childrenVector.get(i)));
}
expr_ref lenAssert(ctx.mk_eq_atom(concat_length, m_autil.mk_add(items.size(), items.c_ptr())), m);
assert_axiom(lenAssert);
}
return concatAst;
}
bool theory_str::can_propagate() {
return !m_basicstr_axiom_todo.empty() || !m_str_eq_todo.empty()
|| !m_concat_axiom_todo.empty() || !m_concat_eval_todo.empty()
|| !m_library_aware_axiom_todo.empty()
|| !m_delayed_axiom_setup_terms.empty();
;
}
void theory_str::propagate() {
context & ctx = get_context();
while (can_propagate()) {
TRACE("str", tout << "propagating..." << std::endl;);
for (unsigned i = 0; i < m_basicstr_axiom_todo.size(); ++i) {
instantiate_basic_string_axioms(m_basicstr_axiom_todo[i]);
}
m_basicstr_axiom_todo.reset();
TRACE("str", tout << "reset m_basicstr_axiom_todo" << std::endl;);
for (unsigned i = 0; i < m_str_eq_todo.size(); ++i) {
std::pair<enode*,enode*> pair = m_str_eq_todo[i];
enode * lhs = pair.first;
enode * rhs = pair.second;
handle_equality(lhs->get_owner(), rhs->get_owner());
}
m_str_eq_todo.reset();
for (unsigned i = 0; i < m_concat_axiom_todo.size(); ++i) {
instantiate_concat_axiom(m_concat_axiom_todo[i]);
}
m_concat_axiom_todo.reset();
for (unsigned i = 0; i < m_concat_eval_todo.size(); ++i) {
try_eval_concat(m_concat_eval_todo[i]);
}
m_concat_eval_todo.reset();
for (unsigned i = 0; i < m_library_aware_axiom_todo.size(); ++i) {
enode * e = m_library_aware_axiom_todo[i];
app * a = e->get_owner();
if (u.str.is_stoi(a)) {
instantiate_axiom_str_to_int(e);
} else if (u.str.is_itos(a)) {
instantiate_axiom_int_to_str(e);
} else if (u.str.is_at(a)) {
instantiate_axiom_CharAt(e);
} else if (u.str.is_prefix(a)) {
instantiate_axiom_prefixof(e);
} else if (u.str.is_suffix(a)) {
instantiate_axiom_suffixof(e);
} else if (u.str.is_contains(a)) {
instantiate_axiom_Contains(e);
} else if (u.str.is_index(a)) {
instantiate_axiom_Indexof(e);
/* TODO NEXT: Indexof2/Lastindexof rewrite?
} else if (is_Indexof2(e)) {
instantiate_axiom_Indexof2(e);
} else if (is_LastIndexof(e)) {
instantiate_axiom_LastIndexof(e);
*/
} else if (u.str.is_extract(a)) {
// TODO check semantics of substr vs. extract
instantiate_axiom_Substr(e);
} else if (u.str.is_replace(a)) {
instantiate_axiom_Replace(e);
} else if (u.str.is_in_re(a)) {
instantiate_axiom_RegexIn(e);
} else {
TRACE("str", tout << "BUG: unhandled library-aware term " << mk_pp(e->get_owner(), get_manager()) << std::endl;);
NOT_IMPLEMENTED_YET();
}
}
m_library_aware_axiom_todo.reset();
for (unsigned i = 0; i < m_delayed_axiom_setup_terms.size(); ++i) {
// I think this is okay
ctx.internalize(m_delayed_axiom_setup_terms[i].get(), false);
set_up_axioms(m_delayed_axiom_setup_terms[i].get());
}
m_delayed_axiom_setup_terms.reset();
}
}
/*
* Attempt to evaluate a concat over constant strings,
* and if this is possible, assert equality between the
* flattened string and the original term.
*/
void theory_str::try_eval_concat(enode * cat) {
app * a_cat = cat->get_owner();
SASSERT(u.str.is_concat(a_cat));
context & ctx = get_context();
ast_manager & m = get_manager();
TRACE("str", tout << "attempting to flatten " << mk_pp(a_cat, m) << std::endl;);
std::stack<app*> worklist;
zstring flattenedString("");
bool constOK = true;
{
app * arg0 = to_app(a_cat->get_arg(0));
app * arg1 = to_app(a_cat->get_arg(1));
worklist.push(arg1);
worklist.push(arg0);
}
while (constOK && !worklist.empty()) {
app * evalArg = worklist.top(); worklist.pop();
zstring nextStr;
if (u.str.is_string(evalArg, nextStr)) {
flattenedString = flattenedString + nextStr;
} else if (u.str.is_concat(evalArg)) {
app * arg0 = to_app(evalArg->get_arg(0));
app * arg1 = to_app(evalArg->get_arg(1));
worklist.push(arg1);
worklist.push(arg0);
} else {
TRACE("str", tout << "non-constant term in concat -- giving up." << std::endl;);
constOK = false;
break;
}
}
if (constOK) {
TRACE("str", tout << "flattened to \"" << flattenedString.encode().c_str() << "\"" << std::endl;);
expr_ref constStr(mk_string(flattenedString), m);
expr_ref axiom(ctx.mk_eq_atom(a_cat, constStr), m);
assert_axiom(axiom);
}
}
/*
* Instantiate an axiom of the following form:
* Length(Concat(x, y)) = Length(x) + Length(y)
*/
void theory_str::instantiate_concat_axiom(enode * cat) {
app * a_cat = cat->get_owner();
SASSERT(u.str.is_concat(a_cat));
ast_manager & m = get_manager();
TRACE("str", tout << "instantiating concat axiom for " << mk_ismt2_pp(a_cat, m) << std::endl;);
// build LHS
expr_ref len_xy(m);
len_xy = mk_strlen(a_cat);
SASSERT(len_xy);
// build RHS: start by extracting x and y from Concat(x, y)
unsigned nArgs = a_cat->get_num_args();
SASSERT(nArgs == 2);
app * a_x = to_app(a_cat->get_arg(0));
app * a_y = to_app(a_cat->get_arg(1));
expr_ref len_x(m);
len_x = mk_strlen(a_x);
SASSERT(len_x);
expr_ref len_y(m);
len_y = mk_strlen(a_y);
SASSERT(len_y);
// now build len_x + len_y
expr_ref len_x_plus_len_y(m);
len_x_plus_len_y = m_autil.mk_add(len_x, len_y);
SASSERT(len_x_plus_len_y);
// finally assert equality between the two subexpressions
app * eq = m.mk_eq(len_xy, len_x_plus_len_y);
SASSERT(eq);
assert_axiom(eq);
}
/*
* Add axioms that are true for any string variable:
* 1. Length(x) >= 0
* 2. Length(x) == 0 <=> x == ""
* If the term is a string constant, we can assert something stronger:
* Length(x) == strlen(x)
*/
void theory_str::instantiate_basic_string_axioms(enode * str) {
context & ctx = get_context();
ast_manager & m = get_manager();
TRACE("str", tout << "set up basic string axioms on " << mk_pp(str->get_owner(), m) << std::endl;);
// TESTING: attempt to avoid a crash here when a variable goes out of scope
if (str->get_iscope_lvl() > ctx.get_scope_level()) {
TRACE("str", tout << "WARNING: skipping axiom setup on out-of-scope string term" << std::endl;);
return;
}
// generate a stronger axiom for constant strings
app * a_str = str->get_owner();
if (u.str.is_string(a_str)) {
expr_ref len_str(m);
len_str = mk_strlen(a_str);
SASSERT(len_str);
zstring strconst;
u.str.is_string(str->get_owner(), strconst);
TRACE("str", tout << "instantiating constant string axioms for \"" << strconst.encode().c_str() << "\"" << std::endl;);
unsigned int l = strconst.length();
expr_ref len(m_autil.mk_numeral(rational(l), true), m);
literal lit(mk_eq(len_str, len, false));
ctx.mark_as_relevant(lit);
ctx.mk_th_axiom(get_id(), 1, &lit);
} else {
// build axiom 1: Length(a_str) >= 0
{
// build LHS
expr_ref len_str(m);
len_str = mk_strlen(a_str);
SASSERT(len_str);
// build RHS
expr_ref zero(m);
zero = m_autil.mk_numeral(rational(0), true);
SASSERT(zero);
// build LHS >= RHS and assert
app * lhs_ge_rhs = m_autil.mk_ge(len_str, zero);
SASSERT(lhs_ge_rhs);
TRACE("str", tout << "string axiom 1: " << mk_ismt2_pp(lhs_ge_rhs, m) << std::endl;);
assert_axiom(lhs_ge_rhs);
}
// build axiom 2: Length(a_str) == 0 <=> a_str == ""
{
// build LHS of iff
expr_ref len_str(m);
len_str = mk_strlen(a_str);
SASSERT(len_str);
expr_ref zero(m);
zero = m_autil.mk_numeral(rational(0), true);
SASSERT(zero);
expr_ref lhs(m);
lhs = ctx.mk_eq_atom(len_str, zero);
SASSERT(lhs);
// build RHS of iff
expr_ref empty_str(m);
empty_str = mk_string("");
SASSERT(empty_str);
expr_ref rhs(m);
rhs = ctx.mk_eq_atom(a_str, empty_str);
SASSERT(rhs);
// build LHS <=> RHS and assert
TRACE("str", tout << "string axiom 2: " << mk_ismt2_pp(lhs, m) << " <=> " << mk_ismt2_pp(rhs, m) << std::endl;);
literal l(mk_eq(lhs, rhs, true));
ctx.mark_as_relevant(l);
ctx.mk_th_axiom(get_id(), 1, &l);
}
}
}
/*
* Add an axiom of the form:
* (lhs == rhs) -> ( Length(lhs) == Length(rhs) )
*/
void theory_str::instantiate_str_eq_length_axiom(enode * lhs, enode * rhs) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * a_lhs = lhs->get_owner();
app * a_rhs = rhs->get_owner();
// build premise: (lhs == rhs)
expr_ref premise(ctx.mk_eq_atom(a_lhs, a_rhs), m);
// build conclusion: ( Length(lhs) == Length(rhs) )
expr_ref len_lhs(mk_strlen(a_lhs), m);
SASSERT(len_lhs);
expr_ref len_rhs(mk_strlen(a_rhs), m);
SASSERT(len_rhs);
expr_ref conclusion(ctx.mk_eq_atom(len_lhs, len_rhs), m);
TRACE("str", tout << "string-eq length-eq axiom: "
<< mk_ismt2_pp(premise, m) << " -> " << mk_ismt2_pp(conclusion, m) << std::endl;);
assert_implication(premise, conclusion);
}
void theory_str::instantiate_axiom_CharAt(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * expr = e->get_owner();
if (axiomatized_terms.contains(expr)) {
TRACE("str", tout << "already set up CharAt axiom for " << mk_pp(expr, m) << std::endl;);
return;
}
axiomatized_terms.insert(expr);
TRACE("str", tout << "instantiate CharAt axiom for " << mk_pp(expr, m) << std::endl;);
expr_ref ts0(mk_str_var("ts0"), m);
expr_ref ts1(mk_str_var("ts1"), m);
expr_ref ts2(mk_str_var("ts2"), m);
expr_ref cond(m.mk_and(
m_autil.mk_ge(expr->get_arg(1), mk_int(0)),
// REWRITE for arithmetic theory:
// m_autil.mk_lt(expr->get_arg(1), mk_strlen(expr->get_arg(0)))
m.mk_not(m_autil.mk_ge(m_autil.mk_add(expr->get_arg(1), m_autil.mk_mul(mk_int(-1), mk_strlen(expr->get_arg(0)))), mk_int(0)))
), m);
expr_ref_vector and_item(m);
and_item.push_back(ctx.mk_eq_atom(expr->get_arg(0), mk_concat(ts0, mk_concat(ts1, ts2))));
and_item.push_back(ctx.mk_eq_atom(expr->get_arg(1), mk_strlen(ts0)));
and_item.push_back(ctx.mk_eq_atom(mk_strlen(ts1), mk_int(1)));
expr_ref thenBranch(m.mk_and(and_item.size(), and_item.c_ptr()), m);
expr_ref elseBranch(ctx.mk_eq_atom(ts1, mk_string("")), m);
expr_ref axiom(m.mk_ite(cond, thenBranch, elseBranch), m);
expr_ref reductionVar(ctx.mk_eq_atom(expr, ts1), m);
SASSERT(axiom);
SASSERT(reductionVar);
expr_ref finalAxiom(m.mk_and(axiom, reductionVar), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
}
void theory_str::instantiate_axiom_prefixof(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * expr = e->get_owner();
if (axiomatized_terms.contains(expr)) {
TRACE("str", tout << "already set up prefixof axiom for " << mk_pp(expr, m) << std::endl;);
return;
}
axiomatized_terms.insert(expr);
TRACE("str", tout << "instantiate prefixof axiom for " << mk_pp(expr, m) << std::endl;);
expr_ref ts0(mk_str_var("ts0"), m);
expr_ref ts1(mk_str_var("ts1"), m);
expr_ref_vector innerItems(m);
innerItems.push_back(ctx.mk_eq_atom(expr->get_arg(1), mk_concat(ts0, ts1)));
innerItems.push_back(ctx.mk_eq_atom(mk_strlen(ts0), mk_strlen(expr->get_arg(0))));
innerItems.push_back(m.mk_ite(ctx.mk_eq_atom(ts0, expr->get_arg(0)), expr, m.mk_not(expr)));
expr_ref then1(m.mk_and(innerItems.size(), innerItems.c_ptr()), m);
SASSERT(then1);
// the top-level condition is Length(arg0) >= Length(arg1)
expr_ref topLevelCond(
m_autil.mk_ge(
m_autil.mk_add(
mk_strlen(expr->get_arg(1)), m_autil.mk_mul(mk_int(-1), mk_strlen(expr->get_arg(0)))),
mk_int(0))
, m);
SASSERT(topLevelCond);
expr_ref finalAxiom(m.mk_ite(topLevelCond, then1, m.mk_not(expr)), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
}
void theory_str::instantiate_axiom_suffixof(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * expr = e->get_owner();
if (axiomatized_terms.contains(expr)) {
TRACE("str", tout << "already set up suffixof axiom for " << mk_pp(expr, m) << std::endl;);
return;
}
axiomatized_terms.insert(expr);
TRACE("str", tout << "instantiate suffixof axiom for " << mk_pp(expr, m) << std::endl;);
expr_ref ts0(mk_str_var("ts0"), m);
expr_ref ts1(mk_str_var("ts1"), m);
expr_ref_vector innerItems(m);
innerItems.push_back(ctx.mk_eq_atom(expr->get_arg(1), mk_concat(ts0, ts1)));
innerItems.push_back(ctx.mk_eq_atom(mk_strlen(ts1), mk_strlen(expr->get_arg(0))));
innerItems.push_back(m.mk_ite(ctx.mk_eq_atom(ts1, expr->get_arg(0)), expr, m.mk_not(expr)));
expr_ref then1(m.mk_and(innerItems.size(), innerItems.c_ptr()), m);
SASSERT(then1);
// the top-level condition is Length(arg0) >= Length(arg1)
expr_ref topLevelCond(
m_autil.mk_ge(
m_autil.mk_add(
mk_strlen(expr->get_arg(1)), m_autil.mk_mul(mk_int(-1), mk_strlen(expr->get_arg(0)))),
mk_int(0))
, m);
SASSERT(topLevelCond);
expr_ref finalAxiom(m.mk_ite(topLevelCond, then1, m.mk_not(expr)), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
}
void theory_str::instantiate_axiom_Contains(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * ex = e->get_owner();
if (axiomatized_terms.contains(ex)) {
TRACE("str", tout << "already set up Contains axiom for " << mk_pp(ex, m) << std::endl;);
return;
}
axiomatized_terms.insert(ex);
// quick path, because this is necessary due to rewriter behaviour
// at minimum it should fix z3str/concat-006.smt2
zstring haystackStr, needleStr;
if (u.str.is_string(ex->get_arg(0), haystackStr) && u.str.is_string(ex->get_arg(1), needleStr)) {
TRACE("str", tout << "eval constant Contains term " << mk_pp(ex, m) << std::endl;);
if (haystackStr.contains(needleStr)) {
assert_axiom(ex);
} else {
assert_axiom(m.mk_not(ex));
}
return;
}
{ // register Contains()
expr * str = ex->get_arg(0);
expr * substr = ex->get_arg(1);
contains_map.push_back(ex);
std::pair<expr*, expr*> key = std::pair<expr*, expr*>(str, substr);
contain_pair_bool_map.insert(str, substr, ex);
contain_pair_idx_map[str].insert(key);
contain_pair_idx_map[substr].insert(key);
}
TRACE("str", tout << "instantiate Contains axiom for " << mk_pp(ex, m) << std::endl;);
expr_ref ts0(mk_str_var("ts0"), m);
expr_ref ts1(mk_str_var("ts1"), m);
expr_ref breakdownAssert(ctx.mk_eq_atom(ex, ctx.mk_eq_atom(ex->get_arg(0), mk_concat(ts0, mk_concat(ex->get_arg(1), ts1)))), m);
SASSERT(breakdownAssert);
assert_axiom(breakdownAssert);
}
void theory_str::instantiate_axiom_Indexof(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * expr = e->get_owner();
if (axiomatized_terms.contains(expr)) {
TRACE("str", tout << "already set up Indexof axiom for " << mk_pp(expr, m) << std::endl;);
return;
}
axiomatized_terms.insert(expr);
TRACE("str", tout << "instantiate Indexof axiom for " << mk_pp(expr, m) << std::endl;);
expr_ref x1(mk_str_var("x1"), m);
expr_ref x2(mk_str_var("x2"), m);
expr_ref indexAst(mk_int_var("index"), m);
expr_ref condAst(mk_contains(expr->get_arg(0), expr->get_arg(1)), m);
SASSERT(condAst);
// -----------------------
// true branch
expr_ref_vector thenItems(m);
// args[0] = x1 . args[1] . x2
thenItems.push_back(ctx.mk_eq_atom(expr->get_arg(0), mk_concat(x1, mk_concat(expr->get_arg(1), x2))));
// indexAst = |x1|
thenItems.push_back(ctx.mk_eq_atom(indexAst, mk_strlen(x1)));
// args[0] = x3 . x4
// /\ |x3| = |x1| + |args[1]| - 1
// /\ ! contains(x3, args[1])
expr_ref x3(mk_str_var("x3"), m);
expr_ref x4(mk_str_var("x4"), m);
expr_ref tmpLen(m_autil.mk_add(indexAst, mk_strlen(expr->get_arg(1)), mk_int(-1)), m);
SASSERT(tmpLen);
thenItems.push_back(ctx.mk_eq_atom(expr->get_arg(0), mk_concat(x3, x4)));
thenItems.push_back(ctx.mk_eq_atom(mk_strlen(x3), tmpLen));
thenItems.push_back(m.mk_not(mk_contains(x3, expr->get_arg(1))));
expr_ref thenBranch(m.mk_and(thenItems.size(), thenItems.c_ptr()), m);
SASSERT(thenBranch);
// -----------------------
// false branch
expr_ref elseBranch(ctx.mk_eq_atom(indexAst, mk_int(-1)), m);
SASSERT(elseBranch);
expr_ref breakdownAssert(m.mk_ite(condAst, thenBranch, elseBranch), m);
SASSERT(breakdownAssert);
expr_ref reduceToIndex(ctx.mk_eq_atom(expr, indexAst), m);
SASSERT(reduceToIndex);
expr_ref finalAxiom(m.mk_and(breakdownAssert, reduceToIndex), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
}
void theory_str::instantiate_axiom_Indexof2(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * expr = e->get_owner();
if (axiomatized_terms.contains(expr)) {
TRACE("str", tout << "already set up Indexof2 axiom for " << mk_pp(expr, m) << std::endl;);
return;
}
axiomatized_terms.insert(expr);
TRACE("str", tout << "instantiate Indexof2 axiom for " << mk_pp(expr, m) << std::endl;);
// -------------------------------------------------------------------------------
// if (arg[2] >= length(arg[0])) // ite2
// resAst = -1
// else
// args[0] = prefix . suffix
// /\ indexAst = indexof(suffix, arg[1])
// /\ args[2] = len(prefix)
// /\ if (indexAst == -1) resAst = indexAst // ite3
// else resAst = args[2] + indexAst
// -------------------------------------------------------------------------------
expr_ref resAst(mk_int_var("res"), m);
expr_ref indexAst(mk_int_var("index"), m);
expr_ref prefix(mk_str_var("prefix"), m);
expr_ref suffix(mk_str_var("suffix"), m);
expr_ref prefixLen(mk_strlen(prefix), m);
expr_ref zeroAst(mk_int(0), m);
expr_ref negOneAst(mk_int(-1), m);
expr_ref ite3(m.mk_ite(
ctx.mk_eq_atom(indexAst, negOneAst),
ctx.mk_eq_atom(resAst, negOneAst),
ctx.mk_eq_atom(resAst, m_autil.mk_add(expr->get_arg(2), indexAst))
),m);
expr_ref_vector ite2ElseItems(m);
ite2ElseItems.push_back(ctx.mk_eq_atom(expr->get_arg(0), mk_concat(prefix, suffix)));
ite2ElseItems.push_back(ctx.mk_eq_atom(indexAst, mk_indexof(suffix, expr->get_arg(1))));
ite2ElseItems.push_back(ctx.mk_eq_atom(expr->get_arg(2), prefixLen));
ite2ElseItems.push_back(ite3);
expr_ref ite2Else(m.mk_and(ite2ElseItems.size(), ite2ElseItems.c_ptr()), m);
SASSERT(ite2Else);
expr_ref ite2(m.mk_ite(
//m_autil.mk_ge(expr->get_arg(2), mk_strlen(expr->get_arg(0))),
m_autil.mk_ge(m_autil.mk_add(expr->get_arg(2), m_autil.mk_mul(mk_int(-1), mk_strlen(expr->get_arg(0)))), zeroAst),
ctx.mk_eq_atom(resAst, negOneAst),
ite2Else
), m);
SASSERT(ite2);
expr_ref ite1(m.mk_ite(
//m_autil.mk_lt(expr->get_arg(2), zeroAst),
m.mk_not(m_autil.mk_ge(expr->get_arg(2), zeroAst)),
ctx.mk_eq_atom(resAst, mk_indexof(expr->get_arg(0), expr->get_arg(1))),
ite2
), m);
SASSERT(ite1);
assert_axiom(ite1);
expr_ref reduceTerm(ctx.mk_eq_atom(expr, resAst), m);
SASSERT(reduceTerm);
assert_axiom(reduceTerm);
}
void theory_str::instantiate_axiom_LastIndexof(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * expr = e->get_owner();
if (axiomatized_terms.contains(expr)) {
TRACE("str", tout << "already set up LastIndexof axiom for " << mk_pp(expr, m) << std::endl;);
return;
}
axiomatized_terms.insert(expr);
TRACE("str", tout << "instantiate LastIndexof axiom for " << mk_pp(expr, m) << std::endl;);
expr_ref x1(mk_str_var("x1"), m);
expr_ref x2(mk_str_var("x2"), m);
expr_ref indexAst(mk_int_var("index"), m);
expr_ref_vector items(m);
// args[0] = x1 . args[1] . x2
expr_ref eq1(ctx.mk_eq_atom(expr->get_arg(0), mk_concat(x1, mk_concat(expr->get_arg(1), x2))), m);
expr_ref arg0HasArg1(mk_contains(expr->get_arg(0), expr->get_arg(1)), m); // arg0HasArg1 = Contains(args[0], args[1])
items.push_back(ctx.mk_eq_atom(arg0HasArg1, eq1));
expr_ref condAst(arg0HasArg1, m);
//----------------------------
// true branch
expr_ref_vector thenItems(m);
thenItems.push_back(m_autil.mk_ge(indexAst, mk_int(0)));
// args[0] = x1 . args[1] . x2
// x1 doesn't contain args[1]
thenItems.push_back(m.mk_not(mk_contains(x2, expr->get_arg(1))));
thenItems.push_back(ctx.mk_eq_atom(indexAst, mk_strlen(x1)));
bool canSkip = false;
zstring arg1Str;
if (u.str.is_string(expr->get_arg(1), arg1Str)) {
if (arg1Str.length() == 1) {
canSkip = true;
}
}
if (!canSkip) {
// args[0] = x3 . x4 /\ |x3| = |x1| + 1 /\ ! contains(x4, args[1])
expr_ref x3(mk_str_var("x3"), m);
expr_ref x4(mk_str_var("x4"), m);
expr_ref tmpLen(m_autil.mk_add(indexAst, mk_int(1)), m);
thenItems.push_back(ctx.mk_eq_atom(expr->get_arg(0), mk_concat(x3, x4)));
thenItems.push_back(ctx.mk_eq_atom(mk_strlen(x3), tmpLen));
thenItems.push_back(m.mk_not(mk_contains(x4, expr->get_arg(1))));
}
//----------------------------
// else branch
expr_ref_vector elseItems(m);
elseItems.push_back(ctx.mk_eq_atom(indexAst, mk_int(-1)));
items.push_back(m.mk_ite(condAst, m.mk_and(thenItems.size(), thenItems.c_ptr()), m.mk_and(elseItems.size(), elseItems.c_ptr())));
expr_ref breakdownAssert(m.mk_and(items.size(), items.c_ptr()), m);
SASSERT(breakdownAssert);
expr_ref reduceToIndex(ctx.mk_eq_atom(expr, indexAst), m);
SASSERT(reduceToIndex);
expr_ref finalAxiom(m.mk_and(breakdownAssert, reduceToIndex), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
}
void theory_str::instantiate_axiom_Substr(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * expr = e->get_owner();
if (axiomatized_terms.contains(expr)) {
TRACE("str", tout << "already set up Substr axiom for " << mk_pp(expr, m) << std::endl;);
return;
}
axiomatized_terms.insert(expr);
TRACE("str", tout << "instantiate Substr axiom for " << mk_pp(expr, m) << std::endl;);
expr_ref substrBase(expr->get_arg(0), m);
expr_ref substrPos(expr->get_arg(1), m);
expr_ref substrLen(expr->get_arg(2), m);
SASSERT(substrBase);
SASSERT(substrPos);
SASSERT(substrLen);
expr_ref zero(m_autil.mk_numeral(rational::zero(), true), m);
expr_ref minusOne(m_autil.mk_numeral(rational::minus_one(), true), m);
SASSERT(zero);
SASSERT(minusOne);
expr_ref_vector argumentsValid_terms(m);
// pos >= 0
argumentsValid_terms.push_back(m_autil.mk_ge(substrPos, zero));
// pos < strlen(base)
// --> pos + -1*strlen(base) < 0
argumentsValid_terms.push_back(m.mk_not(m_autil.mk_ge(
m_autil.mk_add(substrPos, m_autil.mk_mul(minusOne, substrLen)),
zero)));
// len >= 0
argumentsValid_terms.push_back(m_autil.mk_ge(substrLen, zero));
expr_ref argumentsValid(mk_and(argumentsValid_terms), m);
SASSERT(argumentsValid);
ctx.internalize(argumentsValid, false);
// (pos+len) >= strlen(base)
// --> pos + len + -1*strlen(base) >= 0
expr_ref lenOutOfBounds(m_autil.mk_ge(
m_autil.mk_add(substrPos, substrLen, m_autil.mk_mul(minusOne, mk_strlen(substrBase))),
zero), m);
SASSERT(lenOutOfBounds);
ctx.internalize(argumentsValid, false);
// Case 1: pos < 0 or pos >= strlen(base) or len < 0
// ==> (Substr ...) = ""
expr_ref case1_premise(m.mk_not(argumentsValid), m);
SASSERT(case1_premise);
ctx.internalize(case1_premise, false);
expr_ref case1_conclusion(ctx.mk_eq_atom(expr, mk_string("")), m);
SASSERT(case1_conclusion);
ctx.internalize(case1_conclusion, false);
expr_ref case1(rewrite_implication(case1_premise, case1_conclusion), m);
SASSERT(case1);
// Case 2: (pos >= 0 and pos < strlen(base) and len >= 0) and (pos+len) >= strlen(base)
// ==> base = t0.t1 AND len(t0) = pos AND (Substr ...) = t1
expr_ref t0(mk_str_var("t0"), m);
expr_ref t1(mk_str_var("t1"), m);
expr_ref case2_conclusion(m.mk_and(
ctx.mk_eq_atom(substrBase, mk_concat(t0,t1)),
ctx.mk_eq_atom(mk_strlen(t0), substrPos),
ctx.mk_eq_atom(expr, t1)), m);
expr_ref case2(rewrite_implication(m.mk_and(argumentsValid, lenOutOfBounds), case2_conclusion), m);
SASSERT(case2);
// Case 3: (pos >= 0 and pos < strlen(base) and len >= 0) and (pos+len) < strlen(base)
// ==> base = t2.t3.t4 AND len(t2) = pos AND len(t3) = len AND (Substr ...) = t3
expr_ref t2(mk_str_var("t2"), m);
expr_ref t3(mk_str_var("t3"), m);
expr_ref t4(mk_str_var("t4"), m);
expr_ref_vector case3_conclusion_terms(m);
case3_conclusion_terms.push_back(ctx.mk_eq_atom(substrBase, mk_concat(t2, mk_concat(t3, t4))));
case3_conclusion_terms.push_back(ctx.mk_eq_atom(mk_strlen(t2), substrPos));
case3_conclusion_terms.push_back(ctx.mk_eq_atom(mk_strlen(t3), substrLen));
case3_conclusion_terms.push_back(ctx.mk_eq_atom(expr, t3));
expr_ref case3_conclusion(mk_and(case3_conclusion_terms), m);
expr_ref case3(rewrite_implication(m.mk_and(argumentsValid, m.mk_not(lenOutOfBounds)), case3_conclusion), m);
SASSERT(case3);
ctx.internalize(case1, false);
ctx.internalize(case2, false);
ctx.internalize(case3, false);
expr_ref finalAxiom(m.mk_and(case1, case2, case3), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
}
void theory_str::instantiate_axiom_Replace(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * expr = e->get_owner();
if (axiomatized_terms.contains(expr)) {
TRACE("str", tout << "already set up Replace axiom for " << mk_pp(expr, m) << std::endl;);
return;
}
axiomatized_terms.insert(expr);
TRACE("str", tout << "instantiate Replace axiom for " << mk_pp(expr, m) << std::endl;);
expr_ref x1(mk_str_var("x1"), m);
expr_ref x2(mk_str_var("x2"), m);
expr_ref i1(mk_int_var("i1"), m);
expr_ref result(mk_str_var("result"), m);
// condAst = Contains(args[0], args[1])
expr_ref condAst(mk_contains(expr->get_arg(0), expr->get_arg(1)), m);
// -----------------------
// true branch
expr_ref_vector thenItems(m);
// args[0] = x1 . args[1] . x2
thenItems.push_back(ctx.mk_eq_atom(expr->get_arg(0), mk_concat(x1, mk_concat(expr->get_arg(1), x2))));
// i1 = |x1|
thenItems.push_back(ctx.mk_eq_atom(i1, mk_strlen(x1)));
// args[0] = x3 . x4 /\ |x3| = |x1| + |args[1]| - 1 /\ ! contains(x3, args[1])
expr_ref x3(mk_str_var("x3"), m);
expr_ref x4(mk_str_var("x4"), m);
expr_ref tmpLen(m_autil.mk_add(i1, mk_strlen(expr->get_arg(1)), mk_int(-1)), m);
thenItems.push_back(ctx.mk_eq_atom(expr->get_arg(0), mk_concat(x3, x4)));
thenItems.push_back(ctx.mk_eq_atom(mk_strlen(x3), tmpLen));
thenItems.push_back(m.mk_not(mk_contains(x3, expr->get_arg(1))));
thenItems.push_back(ctx.mk_eq_atom(result, mk_concat(x1, mk_concat(expr->get_arg(2), x2))));
// -----------------------
// false branch
expr_ref elseBranch(ctx.mk_eq_atom(result, expr->get_arg(0)), m);
expr_ref breakdownAssert(m.mk_ite(condAst, m.mk_and(thenItems.size(), thenItems.c_ptr()), elseBranch), m);
SASSERT(breakdownAssert);
expr_ref reduceToResult(ctx.mk_eq_atom(expr, result), m);
SASSERT(reduceToResult);
expr_ref finalAxiom(m.mk_and(breakdownAssert, reduceToResult), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
}
void theory_str::instantiate_axiom_str_to_int(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * ex = e->get_owner();
if (axiomatized_terms.contains(ex)) {
TRACE("str", tout << "already set up str.to-int axiom for " << mk_pp(ex, m) << std::endl;);
return;
}
axiomatized_terms.insert(ex);
TRACE("str", tout << "instantiate str.to-int axiom for " << mk_pp(ex, m) << std::endl;);
// let expr = (str.to-int S)
// axiom 1: expr >= -1
// axiom 2: expr = 0 <==> S = "0"
// axiom 3: expr >= 1 ==> len(S) > 0 AND S[0] != "0"
expr * S = ex->get_arg(0);
{
expr_ref axiom1(m_autil.mk_ge(ex, m_autil.mk_numeral(rational::minus_one(), true)), m);
SASSERT(axiom1);
assert_axiom(axiom1);
}
{
expr_ref lhs(ctx.mk_eq_atom(ex, m_autil.mk_numeral(rational::zero(), true)), m);
expr_ref rhs(ctx.mk_eq_atom(S, mk_string("0")), m);
expr_ref axiom2(ctx.mk_eq_atom(lhs, rhs), m);
SASSERT(axiom2);
assert_axiom(axiom2);
}
{
expr_ref premise(m_autil.mk_ge(ex, m_autil.mk_numeral(rational::one(), true)), m);
expr_ref hd(mk_str_var("hd"), m);
expr_ref tl(mk_str_var("tl"), m);
expr_ref conclusion1(ctx.mk_eq_atom(S, mk_concat(hd, tl)), m);
expr_ref conclusion2(ctx.mk_eq_atom(mk_strlen(hd), m_autil.mk_numeral(rational::one(), true)), m);
expr_ref conclusion3(m.mk_not(ctx.mk_eq_atom(hd, mk_string("0"))), m);
expr_ref conclusion(m.mk_and(conclusion1, conclusion2, conclusion3), m);
SASSERT(premise);
SASSERT(conclusion);
assert_implication(premise, conclusion);
}
}
void theory_str::instantiate_axiom_int_to_str(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * ex = e->get_owner();
if (axiomatized_terms.contains(ex)) {
TRACE("str", tout << "already set up str.from-int axiom for " << mk_pp(ex, m) << std::endl;);
return;
}
axiomatized_terms.insert(ex);
TRACE("str", tout << "instantiate str.from-int axiom for " << mk_pp(ex, m) << std::endl;);
// axiom 1: N < 0 <==> (str.from-int N) = ""
expr * N = ex->get_arg(0);
{
expr_ref axiom1_lhs(m.mk_not(m_autil.mk_ge(N, m_autil.mk_numeral(rational::zero(), true))), m);
expr_ref axiom1_rhs(ctx.mk_eq_atom(ex, mk_string("")), m);
expr_ref axiom1(ctx.mk_eq_atom(axiom1_lhs, axiom1_rhs), m);
SASSERT(axiom1);
assert_axiom(axiom1);
}
}
expr * theory_str::mk_RegexIn(expr * str, expr * regexp) {
app * regexIn = u.re.mk_in_re(str, regexp);
// immediately force internalization so that axiom setup does not fail
get_context().internalize(regexIn, false);
set_up_axioms(regexIn);
return regexIn;
}
static zstring str2RegexStr(zstring str) {
zstring res("");
int len = str.length();
for (int i = 0; i < len; i++) {
char nc = str[i];
// 12 special chars
if (nc == '\\' || nc == '^' || nc == '$' || nc == '.' || nc == '|' || nc == '?'
|| nc == '*' || nc == '+' || nc == '(' || nc == ')' || nc == '[' || nc == '{') {
res = res + zstring("\\");
}
char tmp[2] = {(char)str[i], '\0'};
res = res + zstring(tmp);
}
return res;
}
zstring theory_str::get_std_regex_str(expr * regex) {
app * a_regex = to_app(regex);
if (u.re.is_to_re(a_regex)) {
expr * regAst = a_regex->get_arg(0);
zstring regAstVal;
u.str.is_string(regAst, regAstVal);
zstring regStr = str2RegexStr(regAstVal);
return regStr;
} else if (u.re.is_concat(a_regex)) {
expr * reg1Ast = a_regex->get_arg(0);
expr * reg2Ast = a_regex->get_arg(1);
zstring reg1Str = get_std_regex_str(reg1Ast);
zstring reg2Str = get_std_regex_str(reg2Ast);
return zstring("(") + reg1Str + zstring(")(") + reg2Str + zstring(")");
} else if (u.re.is_union(a_regex)) {
expr * reg1Ast = a_regex->get_arg(0);
expr * reg2Ast = a_regex->get_arg(1);
zstring reg1Str = get_std_regex_str(reg1Ast);
zstring reg2Str = get_std_regex_str(reg2Ast);
return zstring("(") + reg1Str + zstring(")|(") + reg2Str + zstring(")");
} else if (u.re.is_star(a_regex)) {
expr * reg1Ast = a_regex->get_arg(0);
zstring reg1Str = get_std_regex_str(reg1Ast);
return zstring("(") + reg1Str + zstring(")*");
} else if (u.re.is_range(a_regex)) {
expr * range1 = a_regex->get_arg(0);
expr * range2 = a_regex->get_arg(1);
zstring range1val, range2val;
u.str.is_string(range1, range1val);
u.str.is_string(range2, range2val);
return zstring("[") + range1val + zstring("-") + range2val + zstring("]");
} else {
TRACE("str", tout << "BUG: unrecognized regex term " << mk_pp(regex, get_manager()) << std::endl;);
UNREACHABLE(); return zstring("");
}
}
void theory_str::instantiate_axiom_RegexIn(enode * e) {
context & ctx = get_context();
ast_manager & m = get_manager();
app * ex = e->get_owner();
if (axiomatized_terms.contains(ex)) {
TRACE("str", tout << "already set up RegexIn axiom for " << mk_pp(ex, m) << std::endl;);
return;
}
axiomatized_terms.insert(ex);
TRACE("str", tout << "instantiate RegexIn axiom for " << mk_pp(ex, m) << std::endl;);
{
zstring regexStr = get_std_regex_str(ex->get_arg(1));
std::pair<expr*, zstring> key1(ex->get_arg(0), regexStr);
// skip Z3str's map check, because we already check if we set up axioms on this term
regex_in_bool_map[key1] = ex;
regex_in_var_reg_str_map[ex->get_arg(0)].insert(regexStr);
}
expr_ref str(ex->get_arg(0), m);
app * regex = to_app(ex->get_arg(1));
if (u.re.is_to_re(regex)) {
expr_ref rxStr(regex->get_arg(0), m);
// want to assert 'expr IFF (str == rxStr)'
expr_ref rhs(ctx.mk_eq_atom(str, rxStr), m);
expr_ref finalAxiom(m.mk_iff(ex, rhs), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
TRACE("str", tout << "set up Str2Reg: (RegexIn " << mk_pp(str, m) << " " << mk_pp(regex, m) << ")" << std::endl;);
} else if (u.re.is_concat(regex)) {
expr_ref var1(mk_regex_rep_var(), m);
expr_ref var2(mk_regex_rep_var(), m);
expr_ref rhs(mk_concat(var1, var2), m);
expr_ref rx1(regex->get_arg(0), m);
expr_ref rx2(regex->get_arg(1), m);
expr_ref var1InRegex1(mk_RegexIn(var1, rx1), m);
expr_ref var2InRegex2(mk_RegexIn(var2, rx2), m);
expr_ref_vector items(m);
items.push_back(var1InRegex1);
items.push_back(var2InRegex2);
items.push_back(ctx.mk_eq_atom(ex, ctx.mk_eq_atom(str, rhs)));
expr_ref finalAxiom(mk_and(items), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
} else if (u.re.is_union(regex)) {
expr_ref var1(mk_regex_rep_var(), m);
expr_ref var2(mk_regex_rep_var(), m);
expr_ref orVar(m.mk_or(ctx.mk_eq_atom(str, var1), ctx.mk_eq_atom(str, var2)), m);
expr_ref regex1(regex->get_arg(0), m);
expr_ref regex2(regex->get_arg(1), m);
expr_ref var1InRegex1(mk_RegexIn(var1, regex1), m);
expr_ref var2InRegex2(mk_RegexIn(var2, regex2), m);
expr_ref_vector items(m);
items.push_back(var1InRegex1);
items.push_back(var2InRegex2);
items.push_back(ctx.mk_eq_atom(ex, orVar));
assert_axiom(mk_and(items));
} else if (u.re.is_star(regex)) {
// slightly more complex due to the unrolling step.
expr_ref regex1(regex->get_arg(0), m);
expr_ref unrollCount(mk_unroll_bound_var(), m);
expr_ref unrollFunc(mk_unroll(regex1, unrollCount), m);
expr_ref_vector items(m);
items.push_back(ctx.mk_eq_atom(ex, ctx.mk_eq_atom(str, unrollFunc)));
items.push_back(ctx.mk_eq_atom(ctx.mk_eq_atom(unrollCount, mk_int(0)), ctx.mk_eq_atom(unrollFunc, mk_string(""))));
expr_ref finalAxiom(mk_and(items), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
} else if (u.re.is_range(regex)) {
// (re.range "A" "Z") unfolds to (re.union "A" "B" ... "Z");
// we rewrite to expr IFF (str = "A" or str = "B" or ... or str = "Z")
expr_ref lo(regex->get_arg(0), m);
expr_ref hi(regex->get_arg(1), m);
zstring str_lo, str_hi;
SASSERT(u.str.is_string(lo));
SASSERT(u.str.is_string(hi));
u.str.is_string(lo, str_lo);
u.str.is_string(hi, str_hi);
SASSERT(str_lo.length() == 1);
SASSERT(str_hi.length() == 1);
unsigned int c1 = str_lo[0];
unsigned int c2 = str_hi[0];
if (c1 > c2) {
// exchange
unsigned int tmp = c1;
c1 = c2;
c2 = tmp;
}
expr_ref_vector range_cases(m);
for (unsigned int ch = c1; ch <= c2; ++ch) {
zstring s_ch(ch);
expr_ref rhs(ctx.mk_eq_atom(str, u.str.mk_string(s_ch)), m);
range_cases.push_back(rhs);
}
expr_ref rhs(mk_or(range_cases), m);
expr_ref finalAxiom(m.mk_iff(ex, rhs), m);
SASSERT(finalAxiom);
assert_axiom(finalAxiom);
} else {
TRACE("str", tout << "ERROR: unknown regex expression " << mk_pp(regex, m) << "!" << std::endl;);
NOT_IMPLEMENTED_YET();
}
}
void theory_str::attach_new_th_var(enode * n) {
context & ctx = get_context();
theory_var v = mk_var(n);
ctx.attach_th_var(n, this, v);
TRACE("str", tout << "new theory var: " << mk_ismt2_pp(n->get_owner(), get_manager()) << " := v#" << v << std::endl;);
}
void theory_str::reset_eh() {
TRACE("str", tout << "resetting" << std::endl;);
m_trail_stack.reset();
m_basicstr_axiom_todo.reset();
m_str_eq_todo.reset();
m_concat_axiom_todo.reset();
pop_scope_eh(get_context().get_scope_level());
}
/*
* Check equality among equivalence class members of LHS and RHS
* to discover an incorrect LHS == RHS.
* For example, if we have y2 == "str3"
* and the equivalence classes are
* { y2, (Concat ce m2) }
* { "str3", (Concat abc x2) }
* then y2 can't be equal to "str3".
* Then add an assertion: (y2 == (Concat ce m2)) AND ("str3" == (Concat abc x2)) -> (y2 != "str3")
*/
bool theory_str::new_eq_check(expr * lhs, expr * rhs) {
context & ctx = get_context();
ast_manager & m = get_manager();
// skip this check if we defer consistency checking, as we can do it for every EQC in final check
if (!opt_DeferEQCConsistencyCheck) {
check_concat_len_in_eqc(lhs);
check_concat_len_in_eqc(rhs);
}
// Now we iterate over all pairs of terms across both EQCs
// and check whether we can show that any pair of distinct terms
// cannot possibly be equal.
// If that's the case, we assert an axiom to that effect and stop.
expr * eqc_nn1 = lhs;
do {
expr * eqc_nn2 = rhs;
do {
TRACE("str", tout << "checking whether " << mk_pp(eqc_nn1, m) << " and " << mk_pp(eqc_nn2, m) << " can be equal" << std::endl;);
// inconsistency check: value
if (!can_two_nodes_eq(eqc_nn1, eqc_nn2)) {
TRACE("str", tout << "inconsistency detected: " << mk_pp(eqc_nn1, m) << " cannot be equal to " << mk_pp(eqc_nn2, m) << std::endl;);
expr_ref to_assert(m.mk_not(ctx.mk_eq_atom(eqc_nn1, eqc_nn2)), m);
assert_axiom(to_assert);
// this shouldn't use the integer theory at all, so we don't allow the option of quick-return
return false;
}
if (!check_length_consistency(eqc_nn1, eqc_nn2)) {
TRACE("str", tout << "inconsistency detected: " << mk_pp(eqc_nn1, m) << " and " << mk_pp(eqc_nn2, m) << " have inconsistent lengths" << std::endl;);
if (opt_NoQuickReturn_IntegerTheory){
TRACE("str", tout << "continuing in new_eq_check() due to opt_NoQuickReturn_IntegerTheory" << std::endl;);
} else {
return false;
}
}
eqc_nn2 = get_eqc_next(eqc_nn2);
} while (eqc_nn2 != rhs);
eqc_nn1 = get_eqc_next(eqc_nn1);
} while (eqc_nn1 != lhs);
if (!contains_map.empty()) {
check_contain_in_new_eq(lhs, rhs);
}
if (!regex_in_bool_map.empty()) {
TRACE("str", tout << "checking regex consistency" << std::endl;);
check_regex_in(lhs, rhs);
}
// okay, all checks here passed
return true;
}
// support for user_smt_theory-style EQC handling
app * theory_str::get_ast(theory_var i) {
return get_enode(i)->get_owner();
}
theory_var theory_str::get_var(expr * n) const {
if (!is_app(n)) {
return null_theory_var;
}
context & ctx = get_context();
if (ctx.e_internalized(to_app(n))) {
enode * e = ctx.get_enode(to_app(n));
return e->get_th_var(get_id());
}
return null_theory_var;
}
// simulate Z3_theory_get_eqc_next()
expr * theory_str::get_eqc_next(expr * n) {
theory_var v = get_var(n);
if (v != null_theory_var) {
theory_var r = m_find.next(v);
return get_ast(r);
}
return n;
}
void theory_str::group_terms_by_eqc(expr * n, std::set<expr*> & concats, std::set<expr*> & vars, std::set<expr*> & consts) {
expr * eqcNode = n;
do {
app * ast = to_app(eqcNode);
if (u.str.is_concat(ast)) {
expr * simConcat = simplify_concat(ast);
if (simConcat != ast) {
if (u.str.is_concat(to_app(simConcat))) {
concats.insert(simConcat);
} else {
if (u.str.is_string(simConcat)) {
consts.insert(simConcat);
} else {
vars.insert(simConcat);
}
}
} else {
concats.insert(simConcat);
}
} else if (u.str.is_string(ast)) {
consts.insert(ast);
} else {
vars.insert(ast);
}
eqcNode = get_eqc_next(eqcNode);
} while (eqcNode != n);
}
void theory_str::get_nodes_in_concat(expr * node, ptr_vector<expr> & nodeList) {
app * a_node = to_app(node);
if (!u.str.is_concat(a_node)) {
nodeList.push_back(node);
return;
} else {
SASSERT(a_node->get_num_args() == 2);
expr * leftArg = a_node->get_arg(0);
expr * rightArg = a_node->get_arg(1);
get_nodes_in_concat(leftArg, nodeList);
get_nodes_in_concat(rightArg, nodeList);
}
}
// previously Concat() in strTheory.cpp
// Evaluates the concatenation (n1 . n2) with respect to
// the current equivalence classes of n1 and n2.
// Returns a constant string expression representing this concatenation
// if one can be determined, or NULL if this is not possible.
expr * theory_str::eval_concat(expr * n1, expr * n2) {
bool n1HasEqcValue = false;
bool n2HasEqcValue = false;
expr * v1 = get_eqc_value(n1, n1HasEqcValue);
expr * v2 = get_eqc_value(n2, n2HasEqcValue);
if (n1HasEqcValue && n2HasEqcValue) {
zstring n1_str, n2_str;
u.str.is_string(v1, n1_str);
u.str.is_string(v2, n2_str);
zstring result = n1_str + n2_str;
return mk_string(result);
} else if (n1HasEqcValue && !n2HasEqcValue) {
zstring v1_str;
u.str.is_string(v1, v1_str);
if (v1_str.empty()) {
return n2;
}
} else if (n2HasEqcValue && !n1HasEqcValue) {
zstring v2_str;
u.str.is_string(v2, v2_str);
if (v2_str.empty()) {
return n1;
}
}
// give up
return NULL;
}
static inline std::string rational_to_string_if_exists(const rational & x, bool x_exists) {
if (x_exists) {
return x.to_string();
} else {
return "?";
}
}
/*
* The inputs:
* ~ nn: non const node
* ~ eq_str: the equivalent constant string of nn
* Iterate the parent of all eqc nodes of nn, looking for:
* ~ concat node
* to see whether some concat nodes can be simplified.
*/
void theory_str::simplify_parent(expr * nn, expr * eq_str) {
ast_manager & m = get_manager();
context & ctx = get_context();
TRACE("str", tout << "simplifying parents of " << mk_ismt2_pp(nn, m)
<< " with respect to " << mk_ismt2_pp(eq_str, m) << std::endl;);
ctx.internalize(nn, false);
zstring eq_strValue;
u.str.is_string(eq_str, eq_strValue);
expr * n_eqNode = nn;
do {
enode * n_eq_enode = ctx.get_enode(n_eqNode);
TRACE("str", tout << "considering all parents of " << mk_ismt2_pp(n_eqNode, m) << std::endl
<< "associated n_eq_enode has " << n_eq_enode->get_num_parents() << " parents" << std::endl;);
// the goal of this next bit is to avoid dereferencing a bogus e_parent in the following loop.
// what I imagine is causing this bug is that, for example, we examine some parent, we add an axiom that involves it,
// and the parent_it iterator becomes invalidated, because we indirectly modified the container that we're iterating over.
enode_vector current_parents;
for (enode_vector::const_iterator parent_it = n_eq_enode->begin_parents(); parent_it != n_eq_enode->end_parents(); parent_it++) {
current_parents.insert(*parent_it);
}
for (enode_vector::iterator parent_it = current_parents.begin(); parent_it != current_parents.end(); ++parent_it) {
enode * e_parent = *parent_it;
SASSERT(e_parent != NULL);
app * a_parent = e_parent->get_owner();
TRACE("str", tout << "considering parent " << mk_ismt2_pp(a_parent, m) << std::endl;);
if (u.str.is_concat(a_parent)) {
expr * arg0 = a_parent->get_arg(0);
expr * arg1 = a_parent->get_arg(1);
rational parentLen;
bool parentLen_exists = get_len_value(a_parent, parentLen);
if (arg0 == n_eq_enode->get_owner()) {
rational arg0Len, arg1Len;
bool arg0Len_exists = get_len_value(eq_str, arg0Len);
bool arg1Len_exists = get_len_value(arg1, arg1Len);
TRACE("str",
tout << "simplify_parent #1:" << std::endl
<< "* parent = " << mk_ismt2_pp(a_parent, m) << std::endl
<< "* |parent| = " << rational_to_string_if_exists(parentLen, parentLen_exists) << std::endl
<< "* |arg0| = " << rational_to_string_if_exists(arg0Len, arg0Len_exists) << std::endl
<< "* |arg1| = " << rational_to_string_if_exists(arg1Len, arg1Len_exists) << std::endl;
);
if (parentLen_exists && !arg1Len_exists) {
TRACE("str", tout << "make up len for arg1" << std::endl;);
expr_ref implyL11(m.mk_and(ctx.mk_eq_atom(mk_strlen(a_parent), mk_int(parentLen)),
ctx.mk_eq_atom(mk_strlen(arg0), mk_int(arg0Len))), m);
rational makeUpLenArg1 = parentLen - arg0Len;
if (makeUpLenArg1.is_nonneg()) {
expr_ref implyR11(ctx.mk_eq_atom(mk_strlen(arg1), mk_int(makeUpLenArg1)), m);
assert_implication(implyL11, implyR11);
} else {
expr_ref neg(m.mk_not(implyL11), m);
assert_axiom(neg);
}
}
// (Concat n_eqNode arg1) /\ arg1 has eq const
expr * concatResult = eval_concat(eq_str, arg1);
if (concatResult != NULL) {
bool arg1HasEqcValue = false;
expr * arg1Value = get_eqc_value(arg1, arg1HasEqcValue);
expr_ref implyL(m);
if (arg1 != arg1Value) {
expr_ref eq_ast1(m);
eq_ast1 = ctx.mk_eq_atom(n_eqNode, eq_str);
SASSERT(eq_ast1);
expr_ref eq_ast2(m);
eq_ast2 = ctx.mk_eq_atom(arg1, arg1Value);
SASSERT(eq_ast2);
implyL = m.mk_and(eq_ast1, eq_ast2);
} else {
implyL = ctx.mk_eq_atom(n_eqNode, eq_str);
}
if (!in_same_eqc(a_parent, concatResult)) {
expr_ref implyR(m);
implyR = ctx.mk_eq_atom(a_parent, concatResult);
SASSERT(implyR);
assert_implication(implyL, implyR);
}
} else if (u.str.is_concat(to_app(n_eqNode))) {
expr_ref simpleConcat(m);
simpleConcat = mk_concat(eq_str, arg1);
if (!in_same_eqc(a_parent, simpleConcat)) {
expr_ref implyL(m);
implyL = ctx.mk_eq_atom(n_eqNode, eq_str);
SASSERT(implyL);
expr_ref implyR(m);
implyR = ctx.mk_eq_atom(a_parent, simpleConcat);
SASSERT(implyR);
assert_implication(implyL, implyR);
}
}
} // if (arg0 == n_eq_enode->get_owner())
if (arg1 == n_eq_enode->get_owner()) {
rational arg0Len, arg1Len;
bool arg0Len_exists = get_len_value(arg0, arg0Len);
bool arg1Len_exists = get_len_value(eq_str, arg1Len);
TRACE("str",
tout << "simplify_parent #2:" << std::endl
<< "* parent = " << mk_ismt2_pp(a_parent, m) << std::endl
<< "* |parent| = " << rational_to_string_if_exists(parentLen, parentLen_exists) << std::endl
<< "* |arg0| = " << rational_to_string_if_exists(arg0Len, arg0Len_exists) << std::endl
<< "* |arg1| = " << rational_to_string_if_exists(arg1Len, arg1Len_exists) << std::endl;
);
if (parentLen_exists && !arg0Len_exists) {
TRACE("str", tout << "make up len for arg0" << std::endl;);
expr_ref implyL11(m.mk_and(ctx.mk_eq_atom(mk_strlen(a_parent), mk_int(parentLen)),
ctx.mk_eq_atom(mk_strlen(arg1), mk_int(arg1Len))), m);
rational makeUpLenArg0 = parentLen - arg1Len;
if (makeUpLenArg0.is_nonneg()) {
expr_ref implyR11(ctx.mk_eq_atom(mk_strlen(arg0), mk_int(makeUpLenArg0)), m);
assert_implication(implyL11, implyR11);
} else {
expr_ref neg(m.mk_not(implyL11), m);
assert_axiom(neg);
}
}
// (Concat arg0 n_eqNode) /\ arg0 has eq const
expr * concatResult = eval_concat(arg0, eq_str);
if (concatResult != NULL) {
bool arg0HasEqcValue = false;
expr * arg0Value = get_eqc_value(arg0, arg0HasEqcValue);
expr_ref implyL(m);
if (arg0 != arg0Value) {
expr_ref eq_ast1(m);
eq_ast1 = ctx.mk_eq_atom(n_eqNode, eq_str);
SASSERT(eq_ast1);
expr_ref eq_ast2(m);
eq_ast2 = ctx.mk_eq_atom(arg0, arg0Value);
SASSERT(eq_ast2);
implyL = m.mk_and(eq_ast1, eq_ast2);
} else {
implyL = ctx.mk_eq_atom(n_eqNode, eq_str);
}
if (!in_same_eqc(a_parent, concatResult)) {
expr_ref implyR(m);
implyR = ctx.mk_eq_atom(a_parent, concatResult);
SASSERT(implyR);
assert_implication(implyL, implyR);
}
} else if (u.str.is_concat(to_app(n_eqNode))) {
expr_ref simpleConcat(m);
simpleConcat = mk_concat(arg0, eq_str);
if (!in_same_eqc(a_parent, simpleConcat)) {
expr_ref implyL(m);
implyL = ctx.mk_eq_atom(n_eqNode, eq_str);
SASSERT(implyL);
expr_ref implyR(m);
implyR = ctx.mk_eq_atom(a_parent, simpleConcat);
SASSERT(implyR);
assert_implication(implyL, implyR);
}
}
} // if (arg1 == n_eq_enode->get_owner
//---------------------------------------------------------
// Case (2-1) begin: (Concat n_eqNode (Concat str var))
if (arg0 == n_eqNode && u.str.is_concat(to_app(arg1))) {
app * a_arg1 = to_app(arg1);
TRACE("str", tout << "simplify_parent #3" << std::endl;);
expr * r_concat_arg0 = a_arg1->get_arg(0);
if (u.str.is_string(r_concat_arg0)) {
expr * combined_str = eval_concat(eq_str, r_concat_arg0);
SASSERT(combined_str);
expr * r_concat_arg1 = a_arg1->get_arg(1);
expr_ref implyL(m);
implyL = ctx.mk_eq_atom(n_eqNode, eq_str);
expr * simplifiedAst = mk_concat(combined_str, r_concat_arg1);
if (!in_same_eqc(a_parent, simplifiedAst)) {
expr_ref implyR(m);
implyR = ctx.mk_eq_atom(a_parent, simplifiedAst);
assert_implication(implyL, implyR);
}
}
}
// Case (2-1) end: (Concat n_eqNode (Concat str var))
//---------------------------------------------------------
//---------------------------------------------------------
// Case (2-2) begin: (Concat (Concat var str) n_eqNode)
if (u.str.is_concat(to_app(arg0)) && arg1 == n_eqNode) {
app * a_arg0 = to_app(arg0);
TRACE("str", tout << "simplify_parent #4" << std::endl;);
expr * l_concat_arg1 = a_arg0->get_arg(1);
if (u.str.is_string(l_concat_arg1)) {
expr * combined_str = eval_concat(l_concat_arg1, eq_str);
SASSERT(combined_str);
expr * l_concat_arg0 = a_arg0->get_arg(0);
expr_ref implyL(m);
implyL = ctx.mk_eq_atom(n_eqNode, eq_str);
expr * simplifiedAst = mk_concat(l_concat_arg0, combined_str);
if (!in_same_eqc(a_parent, simplifiedAst)) {
expr_ref implyR(m);
implyR = ctx.mk_eq_atom(a_parent, simplifiedAst);
assert_implication(implyL, implyR);
}
}
}
// Case (2-2) end: (Concat (Concat var str) n_eqNode)
//---------------------------------------------------------
// Have to look up one more layer: if the parent of the concat is another concat
//-------------------------------------------------
// Case (3-1) begin: (Concat (Concat var n_eqNode) str )
if (arg1 == n_eqNode) {
for (enode_vector::iterator concat_parent_it = e_parent->begin_parents();
concat_parent_it != e_parent->end_parents(); concat_parent_it++) {
enode * e_concat_parent = *concat_parent_it;
app * concat_parent = e_concat_parent->get_owner();
if (u.str.is_concat(concat_parent)) {
expr * concat_parent_arg0 = concat_parent->get_arg(0);
expr * concat_parent_arg1 = concat_parent->get_arg(1);
if (concat_parent_arg0 == a_parent && u.str.is_string(concat_parent_arg1)) {
TRACE("str", tout << "simplify_parent #5" << std::endl;);
expr * combinedStr = eval_concat(eq_str, concat_parent_arg1);
SASSERT(combinedStr);
expr_ref implyL(m);
implyL = ctx.mk_eq_atom(n_eqNode, eq_str);
expr * simplifiedAst = mk_concat(arg0, combinedStr);
if (!in_same_eqc(concat_parent, simplifiedAst)) {
expr_ref implyR(m);
implyR = ctx.mk_eq_atom(concat_parent, simplifiedAst);
assert_implication(implyL, implyR);
}
}
}
}
}
// Case (3-1) end: (Concat (Concat var n_eqNode) str )
// Case (3-2) begin: (Concat str (Concat n_eqNode var) )
if (arg0 == n_eqNode) {
for (enode_vector::iterator concat_parent_it = e_parent->begin_parents();
concat_parent_it != e_parent->end_parents(); concat_parent_it++) {
enode * e_concat_parent = *concat_parent_it;
app * concat_parent = e_concat_parent->get_owner();
if (u.str.is_concat(concat_parent)) {
expr * concat_parent_arg0 = concat_parent->get_arg(0);
expr * concat_parent_arg1 = concat_parent->get_arg(1);
if (concat_parent_arg1 == a_parent && u.str.is_string(concat_parent_arg0)) {
TRACE("str", tout << "simplify_parent #6" << std::endl;);
expr * combinedStr = eval_concat(concat_parent_arg0, eq_str);
SASSERT(combinedStr);
expr_ref implyL(m);
implyL = ctx.mk_eq_atom(n_eqNode, eq_str);
expr * simplifiedAst = mk_concat(combinedStr, arg1);
if (!in_same_eqc(concat_parent, simplifiedAst)) {
expr_ref implyR(m);
implyR = ctx.mk_eq_atom(concat_parent, simplifiedAst);
assert_implication(implyL, implyR);
}
}
}
}
}
// Case (3-2) end: (Concat str (Concat n_eqNode var) )
} // if is_concat(a_parent)
} // for parent_it : n_eq_enode->begin_parents()
// check next EQC member
n_eqNode = get_eqc_next(n_eqNode);
} while (n_eqNode != nn);
}
expr * theory_str::simplify_concat(expr * node) {
ast_manager & m = get_manager();
context & ctx = get_context();
std::map<expr*, expr*> resolvedMap;
ptr_vector<expr> argVec;
get_nodes_in_concat(node, argVec);
for (unsigned i = 0; i < argVec.size(); ++i) {
bool vArgHasEqcValue = false;
expr * vArg = get_eqc_value(argVec[i], vArgHasEqcValue);
if (vArg != argVec[i]) {
resolvedMap[argVec[i]] = vArg;
}
}
if (resolvedMap.size() == 0) {
// no simplification possible
return node;
} else {
expr * resultAst = mk_string("");
for (unsigned i = 0; i < argVec.size(); ++i) {
bool vArgHasEqcValue = false;
expr * vArg = get_eqc_value(argVec[i], vArgHasEqcValue);
resultAst = mk_concat(resultAst, vArg);
}
TRACE("str", tout << mk_ismt2_pp(node, m) << " is simplified to " << mk_ismt2_pp(resultAst, m) << std::endl;);
if (in_same_eqc(node, resultAst)) {
TRACE("str", tout << "SKIP: both concats are already in the same equivalence class" << std::endl;);
} else {
expr_ref_vector items(m);
int pos = 0;
std::map<expr*, expr*>::iterator itor = resolvedMap.begin();
for (; itor != resolvedMap.end(); ++itor) {
items.push_back(ctx.mk_eq_atom(itor->first, itor->second));
pos += 1;
}
expr_ref premise(mk_and(items), m);
expr_ref conclusion(ctx.mk_eq_atom(node, resultAst), m);
assert_implication(premise, conclusion);
}
return resultAst;
}
}
// Modified signature of Z3str2's inferLenConcat().
// Returns true iff nLen can be inferred by this method
// (i.e. the equivalent of a len_exists flag in get_len_value()).
bool theory_str::infer_len_concat(expr * n, rational & nLen) {
context & ctx = get_context();
ast_manager & m = get_manager();
expr * arg0 = to_app(n)->get_arg(0);
expr * arg1 = to_app(n)->get_arg(1);
rational arg0_len, arg1_len;
bool arg0_len_exists = get_len_value(arg0, arg0_len);
bool arg1_len_exists = get_len_value(arg1, arg1_len);
rational tmp_len;
bool nLen_exists = get_len_value(n, tmp_len);
if (arg0_len_exists && arg1_len_exists && !nLen_exists) {
expr_ref_vector l_items(m);
// if (mk_strlen(arg0) != mk_int(arg0_len)) {
{
l_items.push_back(ctx.mk_eq_atom(mk_strlen(arg0), mk_int(arg0_len)));
}
// if (mk_strlen(arg1) != mk_int(arg1_len)) {
{
l_items.push_back(ctx.mk_eq_atom(mk_strlen(arg1), mk_int(arg1_len)));
}
expr_ref axl(m.mk_and(l_items.size(), l_items.c_ptr()), m);
rational nnLen = arg0_len + arg1_len;
expr_ref axr(ctx.mk_eq_atom(mk_strlen(n), mk_int(nnLen)), m);
TRACE("str", tout << "inferred (Length " << mk_pp(n, m) << ") = " << nnLen << std::endl;);
assert_implication(axl, axr);
nLen = nnLen;
return true;
} else {
return false;
}
}
void theory_str::infer_len_concat_arg(expr * n, rational len) {
if (len.is_neg()) {
return;
}
context & ctx = get_context();
ast_manager & m = get_manager();
expr * arg0 = to_app(n)->get_arg(0);
expr * arg1 = to_app(n)->get_arg(1);
rational arg0_len, arg1_len;
bool arg0_len_exists = get_len_value(arg0, arg0_len);
bool arg1_len_exists = get_len_value(arg1, arg1_len);
expr_ref_vector l_items(m);
expr_ref axr(m);
axr.reset();
// if (mk_length(t, n) != mk_int(ctx, len)) {
{
l_items.push_back(ctx.mk_eq_atom(mk_strlen(n), mk_int(len)));
}
if (!arg0_len_exists && arg1_len_exists) {
//if (mk_length(t, arg1) != mk_int(ctx, arg1_len)) {
{
l_items.push_back(ctx.mk_eq_atom(mk_strlen(arg1), mk_int(arg1_len)));
}
rational arg0Len = len - arg1_len;
if (arg0Len.is_nonneg()) {
axr = ctx.mk_eq_atom(mk_strlen(arg0), mk_int(arg0Len));
} else {
// could negate
}
} else if (arg0_len_exists && !arg1_len_exists) {
//if (mk_length(t, arg0) != mk_int(ctx, arg0_len)) {
{
l_items.push_back(ctx.mk_eq_atom(mk_strlen(arg0), mk_int(arg0_len)));
}
rational arg1Len = len - arg0_len;
if (arg1Len.is_nonneg()) {
axr = ctx.mk_eq_atom(mk_strlen(arg1), mk_int(arg1Len));
} else {
// could negate
}
} else {
}
if (axr) {
expr_ref axl(m.mk_and(l_items.size(), l_items.c_ptr()), m);
assert_implication(axl, axr);
}
}
void theory_str::infer_len_concat_equality(expr * nn1, expr * nn2) {
rational nnLen;
bool nnLen_exists = get_len_value(nn1, nnLen);
if (!nnLen_exists) {
nnLen_exists = get_len_value(nn2, nnLen);
}
// case 1:
// Known: a1_arg0 and a1_arg1
// Unknown: nn1
if (u.str.is_concat(to_app(nn1))) {
rational nn1ConcatLen;
bool nn1ConcatLen_exists = infer_len_concat(nn1, nn1ConcatLen);
if (nnLen_exists && nn1ConcatLen_exists) {
nnLen = nn1ConcatLen;
}
}
// case 2:
// Known: a1_arg0 and a1_arg1
// Unknown: nn1
if (u.str.is_concat(to_app(nn2))) {
rational nn2ConcatLen;
bool nn2ConcatLen_exists = infer_len_concat(nn2, nn2ConcatLen);
if (nnLen_exists && nn2ConcatLen_exists) {
nnLen = nn2ConcatLen;
}
}
if (nnLen_exists) {
if (u.str.is_concat(to_app(nn1))) {
infer_len_concat_arg(nn1, nnLen);
}
if (u.str.is_concat(to_app(nn2))) {
infer_len_concat_arg(nn2, nnLen);
}
}
/*
if (isConcatFunc(t, nn2)) {
int nn2ConcatLen = inferLenConcat(t, nn2);
if (nnLen == -1 && nn2ConcatLen != -1)
nnLen = nn2ConcatLen;
}
if (nnLen != -1) {
if (isConcatFunc(t, nn1)) {
inferLenConcatArg(t, nn1, nnLen);
}
if (isConcatFunc(t, nn2)) {
inferLenConcatArg(t, nn2, nnLen);
}
}
*/
}
void theory_str::add_theory_aware_branching_info(expr * term, double priority, lbool phase) {
context & ctx = get_context();
ctx.internalize(term, false);
bool_var v = ctx.get_bool_var(term);
ctx.add_theory_aware_branching_info(v, priority, phase);
}
void theory_str::generate_mutual_exclusion(expr_ref_vector & terms) {
context & ctx = get_context();
// pull each literal out of the arrangement disjunction
literal_vector ls;
for (unsigned i = 0; i < terms.size(); ++i) {
expr * e = terms.get(i);
literal l = ctx.get_literal(e);
ls.push_back(l);
}
ctx.mk_th_case_split(ls.size(), ls.c_ptr());
}
void theory_str::print_cut_var(expr * node, std::ofstream & xout) {
ast_manager & m = get_manager();
xout << "Cut info of " << mk_pp(node, m) << std::endl;
if (cut_var_map.contains(node)) {
if (!cut_var_map[node].empty()) {
xout << "[" << cut_var_map[node].top()->level << "] ";
std::map<expr*, int>::iterator itor = cut_var_map[node].top()->vars.begin();
for (; itor != cut_var_map[node].top()->vars.end(); ++itor) {
xout << mk_pp(itor->first, m) << ", ";
}
xout << std::endl;
}
}
}
/*
* Handle two equivalent Concats.
*/
void theory_str::simplify_concat_equality(expr * nn1, expr * nn2) {
ast_manager & m = get_manager();
context & ctx = get_context();
app * a_nn1 = to_app(nn1);
SASSERT(a_nn1->get_num_args() == 2);
app * a_nn2 = to_app(nn2);
SASSERT(a_nn2->get_num_args() == 2);
expr * a1_arg0 = a_nn1->get_arg(0);
expr * a1_arg1 = a_nn1->get_arg(1);
expr * a2_arg0 = a_nn2->get_arg(0);
expr * a2_arg1 = a_nn2->get_arg(1);
rational a1_arg0_len, a1_arg1_len, a2_arg0_len, a2_arg1_len;
bool a1_arg0_len_exists = get_len_value(a1_arg0, a1_arg0_len);
bool a1_arg1_len_exists = get_len_value(a1_arg1, a1_arg1_len);
bool a2_arg0_len_exists = get_len_value(a2_arg0, a2_arg0_len);
bool a2_arg1_len_exists = get_len_value(a2_arg1, a2_arg1_len);
TRACE("str", tout << "nn1 = " << mk_ismt2_pp(nn1, m) << std::endl
<< "nn2 = " << mk_ismt2_pp(nn2, m) << std::endl;);
TRACE("str", tout
<< "len(" << mk_pp(a1_arg0, m) << ") = " << (a1_arg0_len_exists ? a1_arg0_len.to_string() : "?") << std::endl
<< "len(" << mk_pp(a1_arg1, m) << ") = " << (a1_arg1_len_exists ? a1_arg1_len.to_string() : "?") << std::endl
<< "len(" << mk_pp(a2_arg0, m) << ") = " << (a2_arg0_len_exists ? a2_arg0_len.to_string() : "?") << std::endl
<< "len(" << mk_pp(a2_arg1, m) << ") = " << (a2_arg1_len_exists ? a2_arg1_len.to_string() : "?") << std::endl
<< std::endl;);
infer_len_concat_equality(nn1, nn2);
if (a1_arg0 == a2_arg0) {
if (!in_same_eqc(a1_arg1, a2_arg1)) {
expr_ref premise(ctx.mk_eq_atom(nn1, nn2), m);
expr_ref eq1(ctx.mk_eq_atom(a1_arg1, a2_arg1), m);
expr_ref eq2(ctx.mk_eq_atom(mk_strlen(a1_arg1), mk_strlen(a2_arg1)), m);
expr_ref conclusion(m.mk_and(eq1, eq2), m);
assert_implication(premise, conclusion);
}
TRACE("str", tout << "SKIP: a1_arg0 == a2_arg0" << std::endl;);
return;
}
if (a1_arg1 == a2_arg1) {
if (!in_same_eqc(a1_arg0, a2_arg0)) {
expr_ref premise(ctx.mk_eq_atom(nn1, nn2), m);
expr_ref eq1(ctx.mk_eq_atom(a1_arg0, a2_arg0), m);
expr_ref eq2(ctx.mk_eq_atom(mk_strlen(a1_arg0), mk_strlen(a2_arg0)), m);
expr_ref conclusion(m.mk_and(eq1, eq2), m);
assert_implication(premise, conclusion);
}
TRACE("str", tout << "SKIP: a1_arg1 == a2_arg1" << std::endl;);
return;
}
// quick path
if (in_same_eqc(a1_arg0, a2_arg0)) {
if (in_same_eqc(a1_arg1, a2_arg1)) {
TRACE("str", tout << "SKIP: a1_arg0 =~ a2_arg0 and a1_arg1 =~ a2_arg1" << std::endl;);
return;
} else {
TRACE("str", tout << "quick path 1-1: a1_arg0 =~ a2_arg0" << std::endl;);
expr_ref premise(m.mk_and(ctx.mk_eq_atom(nn1, nn2), ctx.mk_eq_atom(a1_arg0, a2_arg0)), m);
expr_ref conclusion(m.mk_and(ctx.mk_eq_atom(a1_arg1, a2_arg1), ctx.mk_eq_atom(mk_strlen(a1_arg1), mk_strlen(a2_arg1))), m);
assert_implication(premise, conclusion);
return;
}
} else {
if (in_same_eqc(a1_arg1, a2_arg1)) {
TRACE("str", tout << "quick path 1-2: a1_arg1 =~ a2_arg1" << std::endl;);
expr_ref premise(m.mk_and(ctx.mk_eq_atom(nn1, nn2), ctx.mk_eq_atom(a1_arg1, a2_arg1)), m);
expr_ref conclusion(m.mk_and(ctx.mk_eq_atom(a1_arg0, a2_arg0), ctx.mk_eq_atom(mk_strlen(a1_arg0), mk_strlen(a2_arg0))), m);
assert_implication(premise, conclusion);
return;
}
}
// quick path 2-1
if (a1_arg0_len_exists && a2_arg0_len_exists && a1_arg0_len == a2_arg0_len) {
if (!in_same_eqc(a1_arg0, a2_arg0)) {
TRACE("str", tout << "quick path 2-1: len(nn1.arg0) == len(nn2.arg0)" << std::endl;);
expr_ref ax_l1(ctx.mk_eq_atom(nn1, nn2), m);
expr_ref ax_l2(ctx.mk_eq_atom(mk_strlen(a1_arg0), mk_strlen(a2_arg0)), m);
expr_ref ax_r1(ctx.mk_eq_atom(a1_arg0, a2_arg0), m);
expr_ref ax_r2(ctx.mk_eq_atom(a1_arg1, a2_arg1), m);
expr_ref premise(m.mk_and(ax_l1, ax_l2), m);
expr_ref conclusion(m.mk_and(ax_r1, ax_r2), m);
assert_implication(premise, conclusion);
if (opt_NoQuickReturn_IntegerTheory) {
TRACE("str", tout << "bypassing quick return from the end of this case" << std::endl;);
} else {
return;
}
}
}
if (a1_arg1_len_exists && a2_arg1_len_exists && a1_arg1_len == a2_arg1_len) {
if (!in_same_eqc(a1_arg1, a2_arg1)) {
TRACE("str", tout << "quick path 2-2: len(nn1.arg1) == len(nn2.arg1)" << std::endl;);
expr_ref ax_l1(ctx.mk_eq_atom(nn1, nn2), m);
expr_ref ax_l2(ctx.mk_eq_atom(mk_strlen(a1_arg1), mk_strlen(a2_arg1)), m);
expr_ref ax_r1(ctx.mk_eq_atom(a1_arg0, a2_arg0), m);
expr_ref ax_r2(ctx.mk_eq_atom(a1_arg1, a2_arg1), m);
expr_ref premise(m.mk_and(ax_l1, ax_l2), m);
expr_ref conclusion(m.mk_and(ax_r1, ax_r2), m);
assert_implication(premise, conclusion);
if (opt_NoQuickReturn_IntegerTheory) {
TRACE("str", tout << "bypassing quick return from the end of this case" << std::endl;);
} else {
return;
}
}
}
expr_ref new_nn1(simplify_concat(nn1), m);
expr_ref new_nn2(simplify_concat(nn2), m);
app * a_new_nn1 = to_app(new_nn1);
app * a_new_nn2 = to_app(new_nn2);
TRACE("str", tout << "new_nn1 = " << mk_ismt2_pp(new_nn1, m) << std::endl
<< "new_nn2 = " << mk_ismt2_pp(new_nn2, m) << std::endl;);
if (new_nn1 == new_nn2) {
TRACE("str", tout << "equal concats, return" << std::endl;);
return;
}
if (!can_two_nodes_eq(new_nn1, new_nn2)) {
expr_ref detected(m.mk_not(ctx.mk_eq_atom(new_nn1, new_nn2)), m);
TRACE("str", tout << "inconsistency detected: " << mk_ismt2_pp(detected, m) << std::endl;);
assert_axiom(detected);
return;
}
// check whether new_nn1 and new_nn2 are still concats
bool n1IsConcat = u.str.is_concat(a_new_nn1);
bool n2IsConcat = u.str.is_concat(a_new_nn2);
if (!n1IsConcat && n2IsConcat) {
TRACE("str", tout << "nn1_new is not a concat" << std::endl;);
if (u.str.is_string(a_new_nn1)) {
simplify_parent(new_nn2, new_nn1);
}
return;
} else if (n1IsConcat && !n2IsConcat) {
TRACE("str", tout << "nn2_new is not a concat" << std::endl;);
if (u.str.is_string(a_new_nn2)) {
simplify_parent(new_nn1, new_nn2);
}
return;
} else if (!n1IsConcat && !n2IsConcat) {
// normally this should never happen, because group_terms_by_eqc() should have pre-simplified
// as much as possible. however, we make a defensive check here just in case
TRACE("str", tout << "WARNING: nn1_new and nn2_new both simplify to non-concat terms" << std::endl;);
return;
}
expr * v1_arg0 = a_new_nn1->get_arg(0);
expr * v1_arg1 = a_new_nn1->get_arg(1);
expr * v2_arg0 = a_new_nn2->get_arg(0);
expr * v2_arg1 = a_new_nn2->get_arg(1);
if (!in_same_eqc(new_nn1, new_nn2) && (nn1 != new_nn1 || nn2 != new_nn2)) {
int ii4 = 0;
expr* item[3];
if (nn1 != new_nn1) {
item[ii4++] = ctx.mk_eq_atom(nn1, new_nn1);
}
if (nn2 != new_nn2) {
item[ii4++] = ctx.mk_eq_atom(nn2, new_nn2);
}
item[ii4++] = ctx.mk_eq_atom(nn1, nn2);
expr_ref premise(m.mk_and(ii4, item), m);
expr_ref conclusion(ctx.mk_eq_atom(new_nn1, new_nn2), m);
assert_implication(premise, conclusion);
}
// start to split both concats
check_and_init_cut_var(v1_arg0);
check_and_init_cut_var(v1_arg1);
check_and_init_cut_var(v2_arg0);
check_and_init_cut_var(v2_arg1);
//*************************************************************
// case 1: concat(x, y) = concat(m, n)
//*************************************************************
if (is_concat_eq_type1(new_nn1, new_nn2)) {
process_concat_eq_type1(new_nn1, new_nn2);
return;
}
//*************************************************************
// case 2: concat(x, y) = concat(m, "str")
//*************************************************************
if (is_concat_eq_type2(new_nn1, new_nn2)) {
process_concat_eq_type2(new_nn1, new_nn2);
return;
}
//*************************************************************
// case 3: concat(x, y) = concat("str", n)
//*************************************************************
if (is_concat_eq_type3(new_nn1, new_nn2)) {
process_concat_eq_type3(new_nn1, new_nn2);
return;
}
//*************************************************************
// case 4: concat("str1", y) = concat("str2", n)
//*************************************************************
if (is_concat_eq_type4(new_nn1, new_nn2)) {
process_concat_eq_type4(new_nn1, new_nn2);
return;
}
//*************************************************************
// case 5: concat(x, "str1") = concat(m, "str2")
//*************************************************************
if (is_concat_eq_type5(new_nn1, new_nn2)) {
process_concat_eq_type5(new_nn1, new_nn2);
return;
}
//*************************************************************
// case 6: concat("str1", y) = concat(m, "str2")
//*************************************************************
if (is_concat_eq_type6(new_nn1, new_nn2)) {
process_concat_eq_type6(new_nn1, new_nn2);
return;
}
}
/*
* Returns true if attempting to process a concat equality between lhs and rhs
* will result in overlapping variables (false otherwise).
*/
bool theory_str::will_result_in_overlap(expr * lhs, expr * rhs) {
ast_manager & m = get_manager();
expr_ref new_nn1(simplify_concat(lhs), m);
expr_ref new_nn2(simplify_concat(rhs), m);
app * a_new_nn1 = to_app(new_nn1);
app * a_new_nn2 = to_app(new_nn2);
bool n1IsConcat = u.str.is_concat(a_new_nn1);
bool n2IsConcat = u.str.is_concat(a_new_nn2);
if (!n1IsConcat && !n2IsConcat) {
// we simplified both sides to non-concat expressions...
return false;
}
expr * v1_arg0 = a_new_nn1->get_arg(0);
expr * v1_arg1 = a_new_nn1->get_arg(1);
expr * v2_arg0 = a_new_nn2->get_arg(0);
expr * v2_arg1 = a_new_nn2->get_arg(1);
TRACE("str", tout << "checking whether " << mk_pp(new_nn1, m) << " and " << mk_pp(new_nn1, m) << " might overlap." << std::endl;);
check_and_init_cut_var(v1_arg0);
check_and_init_cut_var(v1_arg1);
check_and_init_cut_var(v2_arg0);
check_and_init_cut_var(v2_arg1);
//*************************************************************
// case 1: concat(x, y) = concat(m, n)
//*************************************************************
if (is_concat_eq_type1(new_nn1, new_nn2)) {
TRACE("str", tout << "Type 1 check." << std::endl;);
expr * x = to_app(new_nn1)->get_arg(0);
expr * y = to_app(new_nn1)->get_arg(1);
expr * m = to_app(new_nn2)->get_arg(0);
expr * n = to_app(new_nn2)->get_arg(1);
if (has_self_cut(m, y)) {
TRACE("str", tout << "Possible overlap found" << std::endl; print_cut_var(m, tout); print_cut_var(y, tout););
return true;
} else if (has_self_cut(x, n)) {
TRACE("str", tout << "Possible overlap found" << std::endl; print_cut_var(x, tout); print_cut_var(n, tout););
return true;
} else {
return false;
}
}
//*************************************************************
// case 2: concat(x, y) = concat(m, "str")
//*************************************************************
if (is_concat_eq_type2(new_nn1, new_nn2)) {
expr * y = NULL;
expr * m = NULL;
expr * v1_arg0 = to_app(new_nn1)->get_arg(0);
expr * v1_arg1 = to_app(new_nn1)->get_arg(1);
expr * v2_arg0 = to_app(new_nn2)->get_arg(0);
expr * v2_arg1 = to_app(new_nn2)->get_arg(1);
if (u.str.is_string(v1_arg1) && !u.str.is_string(v2_arg1)) {
m = v1_arg0;
y = v2_arg1;
} else {
m = v2_arg0;
y = v1_arg1;
}
if (has_self_cut(m, y)) {
TRACE("str", tout << "Possible overlap found" << std::endl; print_cut_var(m, tout); print_cut_var(y, tout););
return true;
} else {
return false;
}
}
//*************************************************************
// case 3: concat(x, y) = concat("str", n)
//*************************************************************
if (is_concat_eq_type3(new_nn1, new_nn2)) {
expr * v1_arg0 = to_app(new_nn1)->get_arg(0);
expr * v1_arg1 = to_app(new_nn1)->get_arg(1);
expr * v2_arg0 = to_app(new_nn2)->get_arg(0);
expr * v2_arg1 = to_app(new_nn2)->get_arg(1);
expr * x = NULL;
expr * n = NULL;
if (u.str.is_string(v1_arg0) && !u.str.is_string(v2_arg0)) {
n = v1_arg1;
x = v2_arg0;
} else {
n = v2_arg1;
x = v1_arg0;
}
if (has_self_cut(x, n)) {
TRACE("str", tout << "Possible overlap found" << std::endl; print_cut_var(x, tout); print_cut_var(n, tout););
return true;
} else {
return false;
}
}
//*************************************************************
// case 4: concat("str1", y) = concat("str2", n)
//*************************************************************
if (is_concat_eq_type4(new_nn1, new_nn2)) {
// This case can never result in an overlap.
return false;
}
//*************************************************************
// case 5: concat(x, "str1") = concat(m, "str2")
//*************************************************************
if (is_concat_eq_type5(new_nn1, new_nn2)) {
// This case can never result in an overlap.
return false;
}
//*************************************************************
// case 6: concat("str1", y) = concat(m, "str2")
//*************************************************************
if (is_concat_eq_type6(new_nn1, new_nn2)) {
expr * v1_arg0 = to_app(new_nn1)->get_arg(0);
expr * v1_arg1 = to_app(new_nn1)->get_arg(1);
expr * v2_arg0 = to_app(new_nn2)->get_arg(0);
expr * v2_arg1 = to_app(new_nn2)->get_arg(1);
expr * y = NULL;
expr * m = NULL;
if (u.str.is_string(v1_arg0)) {
y = v1_arg1;
m = v2_arg0;
} else {
y = v2_arg1;
m = v1_arg0;
}
if (has_self_cut(m, y)) {
TRACE("str", tout << "Possible overlap found" << std::endl; print_cut_var(m, tout); print_cut_var(y, tout););
return true;
} else {
return false;
}
}
TRACE("str", tout << "warning: unrecognized concat case" << std::endl;);
return false;
}
/*************************************************************
* Type 1: concat(x, y) = concat(m, n)
* x, y, m and n all variables
*************************************************************/
bool theory_str::is_concat_eq_type1(expr * concatAst1, expr * concatAst2) {
expr * x = to_app(concatAst1)->get_arg(0);
expr * y = to_app(concatAst1)->get_arg(1);
expr * m = to_app(concatAst2)->get_arg(0);
expr * n = to_app(concatAst2)->get_arg(1);
if (!u.str.is_string(x) && !u.str.is_string(y) && !u.str.is_string(m) && !u.str.is_string(n)) {
return true;
} else {
return false;
}
}
void theory_str::process_concat_eq_type1(expr * concatAst1, expr * concatAst2) {
ast_manager & mgr = get_manager();
context & ctx = get_context();
bool overlapAssumptionUsed = false;
TRACE("str", tout << "process_concat_eq TYPE 1" << std::endl
<< "concatAst1 = " << mk_ismt2_pp(concatAst1, mgr) << std::endl
<< "concatAst2 = " << mk_ismt2_pp(concatAst2, mgr) << std::endl;
);
if (!u.str.is_concat(to_app(concatAst1))) {
TRACE("str", tout << "concatAst1 is not a concat function" << std::endl;);
return;
}
if (!u.str.is_concat(to_app(concatAst2))) {
TRACE("str", tout << "concatAst2 is not a concat function" << std::endl;);
return;
}
expr * x = to_app(concatAst1)->get_arg(0);
expr * y = to_app(concatAst1)->get_arg(1);
expr * m = to_app(concatAst2)->get_arg(0);
expr * n = to_app(concatAst2)->get_arg(1);
rational x_len, y_len, m_len, n_len;
bool x_len_exists = get_len_value(x, x_len);
bool y_len_exists = get_len_value(y, y_len);
bool m_len_exists = get_len_value(m, m_len);
bool n_len_exists = get_len_value(n, n_len);
int splitType = -1;
if (x_len_exists && m_len_exists) {
TRACE("str", tout << "length values found: x/m" << std::endl;);
if (x_len < m_len) {
splitType = 0;
} else if (x_len == m_len) {
splitType = 1;
} else {
splitType = 2;
}
}
if (splitType == -1 && y_len_exists && n_len_exists) {
TRACE("str", tout << "length values found: y/n" << std::endl;);
if (y_len > n_len) {
splitType = 0;
} else if (y_len == n_len) {
splitType = 1;
} else {
splitType = 2;
}
}
TRACE("str", tout
<< "len(x) = " << (x_len_exists ? x_len.to_string() : "?") << std::endl
<< "len(y) = " << (y_len_exists ? y_len.to_string() : "?") << std::endl
<< "len(m) = " << (m_len_exists ? m_len.to_string() : "?") << std::endl
<< "len(n) = " << (n_len_exists ? n_len.to_string() : "?") << std::endl
<< "split type " << splitType << std::endl;
);
expr * t1 = NULL;
expr * t2 = NULL;
expr * xorFlag = NULL;
std::pair<expr*, expr*> key1(concatAst1, concatAst2);
std::pair<expr*, expr*> key2(concatAst2, concatAst1);
// check the entries in this map to make sure they're still in scope
// before we use them.
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry1 = varForBreakConcat.find(key1);
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry2 = varForBreakConcat.find(key2);
bool entry1InScope;
if (entry1 == varForBreakConcat.end()) {
entry1InScope = false;
} else {
if (internal_variable_set.find((entry1->second)[0]) == internal_variable_set.end()
|| internal_variable_set.find((entry1->second)[1]) == internal_variable_set.end()
/*|| internal_variable_set.find((entry1->second)[2]) == internal_variable_set.end() */) {
entry1InScope = false;
} else {
entry1InScope = true;
}
}
bool entry2InScope;
if (entry2 == varForBreakConcat.end()) {
entry2InScope = false;
} else {
if (internal_variable_set.find((entry2->second)[0]) == internal_variable_set.end()
|| internal_variable_set.find((entry2->second)[1]) == internal_variable_set.end()
/* || internal_variable_set.find((entry2->second)[2]) == internal_variable_set.end() */) {
entry2InScope = false;
} else {
entry2InScope = true;
}
}
TRACE("str", tout << "entry 1 " << (entry1InScope ? "in scope" : "not in scope") << std::endl
<< "entry 2 " << (entry2InScope ? "in scope" : "not in scope") << std::endl;);
if (!entry1InScope && !entry2InScope) {
t1 = mk_nonempty_str_var();
t2 = mk_nonempty_str_var();
xorFlag = mk_internal_xor_var();
check_and_init_cut_var(t1);
check_and_init_cut_var(t2);
varForBreakConcat[key1][0] = t1;
varForBreakConcat[key1][1] = t2;
varForBreakConcat[key1][2] = xorFlag;
} else {
// match found
if (entry1InScope) {
t1 = varForBreakConcat[key1][0];
t2 = varForBreakConcat[key1][1];
xorFlag = varForBreakConcat[key1][2];
} else {
t1 = varForBreakConcat[key2][0];
t2 = varForBreakConcat[key2][1];
xorFlag = varForBreakConcat[key2][2];
}
refresh_theory_var(t1);
add_nonempty_constraint(t1);
refresh_theory_var(t2);
add_nonempty_constraint(t2);
}
// For split types 0 through 2, we can get away with providing
// fewer split options since more length information is available.
if (splitType == 0) {
//--------------------------------------
// Type 0: M cuts Y.
// len(x) < len(m) || len(y) > len(n)
//--------------------------------------
expr_ref_vector ax_l_items(mgr);
expr_ref_vector ax_r_items(mgr);
ax_l_items.push_back(ctx.mk_eq_atom(concatAst1, concatAst2));
expr_ref x_t1(mk_concat(x, t1), mgr);
expr_ref t1_n(mk_concat(t1, n), mgr);
ax_r_items.push_back(ctx.mk_eq_atom(m, x_t1));
ax_r_items.push_back(ctx.mk_eq_atom(y, t1_n));
if (m_len_exists && x_len_exists) {
ax_l_items.push_back(ctx.mk_eq_atom(mk_strlen(x), mk_int(x_len)));
ax_l_items.push_back(ctx.mk_eq_atom(mk_strlen(m), mk_int(m_len)));
rational m_sub_x = m_len - x_len;
ax_r_items.push_back(ctx.mk_eq_atom(mk_strlen(t1), mk_int(m_sub_x)));
} else {
ax_l_items.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_int(y_len)));
ax_l_items.push_back(ctx.mk_eq_atom(mk_strlen(n), mk_int(n_len)));
rational y_sub_n = y_len - n_len;
ax_r_items.push_back(ctx.mk_eq_atom(mk_strlen(t1), mk_int(y_sub_n)));
}
expr_ref ax_l(mk_and(ax_l_items), mgr);
expr_ref ax_r(mk_and(ax_r_items), mgr);
if (!has_self_cut(m, y)) {
// Cut Info
add_cut_info_merge(t1, sLevel, m);
add_cut_info_merge(t1, sLevel, y);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(ax_l, ax_r), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ax_l, ax_r);
}
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
assert_implication(ax_l, tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIPPED" << std::endl;);
TRACE("str", {print_cut_var(m, tout); print_cut_var(y, tout);});
if (!overlapAssumptionUsed) {
overlapAssumptionUsed = true;
assert_implication(ax_l, m_theoryStrOverlapAssumption_term);
}
}
}
} else if (splitType == 1) {
// Type 1:
// len(x) = len(m) || len(y) = len(n)
expr_ref ax_l1(ctx.mk_eq_atom(concatAst1, concatAst2), mgr);
expr_ref ax_l2(mgr.mk_or(ctx.mk_eq_atom(mk_strlen(x), mk_strlen(m)), ctx.mk_eq_atom(mk_strlen(y), mk_strlen(n))), mgr);
expr_ref ax_l(mgr.mk_and(ax_l1, ax_l2), mgr);
expr_ref ax_r(mgr.mk_and(ctx.mk_eq_atom(x,m), ctx.mk_eq_atom(y,n)), mgr);
assert_implication(ax_l, ax_r);
} else if (splitType == 2) {
// Type 2: X cuts N.
// len(x) > len(m) || len(y) < len(n)
expr_ref m_t2(mk_concat(m, t2), mgr);
expr_ref t2_y(mk_concat(t2, y), mgr);
expr_ref_vector ax_l_items(mgr);
ax_l_items.push_back(ctx.mk_eq_atom(concatAst1, concatAst2));
expr_ref_vector ax_r_items(mgr);
ax_r_items.push_back(ctx.mk_eq_atom(x, m_t2));
ax_r_items.push_back(ctx.mk_eq_atom(t2_y, n));
if (m_len_exists && x_len_exists) {
ax_l_items.push_back(ctx.mk_eq_atom(mk_strlen(x), mk_int(x_len)));
ax_l_items.push_back(ctx.mk_eq_atom(mk_strlen(m), mk_int(m_len)));
rational x_sub_m = x_len - m_len;
ax_r_items.push_back(ctx.mk_eq_atom(mk_strlen(t2), mk_int(x_sub_m)));
} else {
ax_l_items.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_int(y_len)));
ax_l_items.push_back(ctx.mk_eq_atom(mk_strlen(n), mk_int(n_len)));
rational n_sub_y = n_len - y_len;
ax_r_items.push_back(ctx.mk_eq_atom(mk_strlen(t2), mk_int(n_sub_y)));
}
expr_ref ax_l(mk_and(ax_l_items), mgr);
expr_ref ax_r(mk_and(ax_r_items), mgr);
if (!has_self_cut(x, n)) {
// Cut Info
add_cut_info_merge(t2, sLevel, x);
add_cut_info_merge(t2, sLevel, n);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(ax_l, ax_r), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ax_l, ax_r);
}
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
assert_implication(ax_l, tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIPPED" << std::endl;);
TRACE("str", {print_cut_var(m, tout); print_cut_var(y, tout);});
if (!overlapAssumptionUsed) {
overlapAssumptionUsed = true;
assert_implication(ax_l, m_theoryStrOverlapAssumption_term);
}
}
}
} else if (splitType == -1) {
// Here we don't really have a choice. We have no length information at all...
// This vector will eventually contain one term for each possible arrangement we explore.
expr_ref_vector arrangement_disjunction(mgr);
// break option 1: m cuts y
// len(x) < len(m) || len(y) > len(n)
if (!avoidLoopCut || !has_self_cut(m, y)) {
expr_ref_vector and_item(mgr);
// break down option 1-1
expr_ref x_t1(mk_concat(x, t1), mgr);
expr_ref t1_n(mk_concat(t1, n), mgr);
and_item.push_back(ctx.mk_eq_atom(m, x_t1));
and_item.push_back(ctx.mk_eq_atom(y, t1_n));
expr_ref x_plus_t1(m_autil.mk_add(mk_strlen(x), mk_strlen(t1)), mgr);
and_item.push_back(ctx.mk_eq_atom(mk_strlen(m), x_plus_t1));
// These were crashing the solver because the integer theory
// expects a constant on the right-hand side.
// The things we want to assert here are len(m) > len(x) and len(y) > len(n).
// We rewrite A > B as A-B > 0 and then as not(A-B <= 0),
// and then, *because we aren't allowed to use subtraction*,
// as not(A + -1*B <= 0)
and_item.push_back(
mgr.mk_not(m_autil.mk_le(
m_autil.mk_add(mk_strlen(m), m_autil.mk_mul(mk_int(-1), mk_strlen(x))),
mk_int(0))) );
and_item.push_back(
mgr.mk_not(m_autil.mk_le(
m_autil.mk_add(mk_strlen(y),m_autil.mk_mul(mk_int(-1), mk_strlen(n))),
mk_int(0))) );
expr_ref option1(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option1);
add_theory_aware_branching_info(option1, 0.1, l_true);
add_cut_info_merge(t1, ctx.get_scope_level(), m);
add_cut_info_merge(t1, ctx.get_scope_level(), y);
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
arrangement_disjunction.push_back(tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIPPED" << std::endl;);
TRACE("str", {print_cut_var(m, tout); print_cut_var(y, tout);});
if (!overlapAssumptionUsed) {
overlapAssumptionUsed = true;
arrangement_disjunction.push_back(m_theoryStrOverlapAssumption_term);
}
}
}
// break option 2:
// x = m . t2
// n = t2 . y
if (!avoidLoopCut || !has_self_cut(x, n)) {
expr_ref_vector and_item(mgr);
// break down option 1-2
expr_ref m_t2(mk_concat(m, t2), mgr);
expr_ref t2_y(mk_concat(t2, y), mgr);
and_item.push_back(ctx.mk_eq_atom(x, m_t2));
and_item.push_back(ctx.mk_eq_atom(n, t2_y));
expr_ref m_plus_t2(m_autil.mk_add(mk_strlen(m), mk_strlen(t2)), mgr);
and_item.push_back(ctx.mk_eq_atom(mk_strlen(x), m_plus_t2));
// want len(x) > len(m) and len(n) > len(y)
and_item.push_back(
mgr.mk_not(m_autil.mk_le(
m_autil.mk_add(mk_strlen(x), m_autil.mk_mul(mk_int(-1), mk_strlen(m))),
mk_int(0))) );
and_item.push_back(
mgr.mk_not(m_autil.mk_le(
m_autil.mk_add(mk_strlen(n), m_autil.mk_mul(mk_int(-1), mk_strlen(y))),
mk_int(0))) );
expr_ref option2(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option2);
add_theory_aware_branching_info(option2, 0.1, l_true);
add_cut_info_merge(t2, ctx.get_scope_level(), x);
add_cut_info_merge(t2, ctx.get_scope_level(), n);
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
arrangement_disjunction.push_back(tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIPPED" << std::endl;);
TRACE("str", {print_cut_var(x, tout); print_cut_var(n, tout);});
if (!overlapAssumptionUsed) {
overlapAssumptionUsed = true;
arrangement_disjunction.push_back(m_theoryStrOverlapAssumption_term);
}
}
}
// option 3:
// x = m, y = n
if (can_two_nodes_eq(x, m) && can_two_nodes_eq(y, n)) {
expr_ref_vector and_item(mgr);
and_item.push_back(ctx.mk_eq_atom(x, m));
and_item.push_back(ctx.mk_eq_atom(y, n));
and_item.push_back(ctx.mk_eq_atom(mk_strlen(x), mk_strlen(m)));
and_item.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_strlen(n)));
expr_ref option3(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option3);
// prioritize this case, it is easier
add_theory_aware_branching_info(option3, 0.5, l_true);
}
if (!arrangement_disjunction.empty()) {
expr_ref premise(ctx.mk_eq_atom(concatAst1, concatAst2), mgr);
expr_ref conclusion(mk_or(arrangement_disjunction), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(premise, conclusion), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(premise, conclusion);
}
// assert mutual exclusion between each branch of the arrangement
generate_mutual_exclusion(arrangement_disjunction);
} else {
TRACE("str", tout << "STOP: no split option found for two EQ concats." << std::endl;);
}
} // (splitType == -1)
}
/*************************************************************
* Type 2: concat(x, y) = concat(m, "str")
*************************************************************/
bool theory_str::is_concat_eq_type2(expr * concatAst1, expr * concatAst2) {
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
if ((!u.str.is_string(v1_arg0)) && u.str.is_string(v1_arg1)
&& (!u.str.is_string(v2_arg0)) && (!u.str.is_string(v2_arg1))) {
return true;
} else if ((!u.str.is_string(v2_arg0)) && u.str.is_string(v2_arg1)
&& (!u.str.is_string(v1_arg0)) && (!u.str.is_string(v1_arg1))) {
return true;
} else {
return false;
}
}
void theory_str::process_concat_eq_type2(expr * concatAst1, expr * concatAst2) {
ast_manager & mgr = get_manager();
context & ctx = get_context();
bool overlapAssumptionUsed = false;
TRACE("str", tout << "process_concat_eq TYPE 2" << std::endl
<< "concatAst1 = " << mk_ismt2_pp(concatAst1, mgr) << std::endl
<< "concatAst2 = " << mk_ismt2_pp(concatAst2, mgr) << std::endl;
);
if (!u.str.is_concat(to_app(concatAst1))) {
TRACE("str", tout << "concatAst1 is not a concat function" << std::endl;);
return;
}
if (!u.str.is_concat(to_app(concatAst2))) {
TRACE("str", tout << "concatAst2 is not a concat function" << std::endl;);
return;
}
expr * x = NULL;
expr * y = NULL;
expr * strAst = NULL;
expr * m = NULL;
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
if (u.str.is_string(v1_arg1) && !u.str.is_string(v2_arg1)) {
m = v1_arg0;
strAst = v1_arg1;
x = v2_arg0;
y = v2_arg1;
} else {
m = v2_arg0;
strAst = v2_arg1;
x = v1_arg0;
y = v1_arg1;
}
zstring strValue;
u.str.is_string(strAst, strValue);
rational x_len, y_len, m_len, str_len;
bool x_len_exists = get_len_value(x, x_len);
bool y_len_exists = get_len_value(y, y_len);
bool m_len_exists = get_len_value(m, m_len);
bool str_len_exists = true;
str_len = rational(strValue.length());
// setup
expr * xorFlag = NULL;
expr * temp1 = NULL;
std::pair<expr*, expr*> key1(concatAst1, concatAst2);
std::pair<expr*, expr*> key2(concatAst2, concatAst1);
// check the entries in this map to make sure they're still in scope
// before we use them.
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry1 = varForBreakConcat.find(key1);
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry2 = varForBreakConcat.find(key2);
// prevent checking scope for the XOR term, as it's always in the same scope as the split var
bool entry1InScope;
if (entry1 == varForBreakConcat.end()) {
entry1InScope = false;
} else {
if (internal_variable_set.find((entry1->second)[0]) == internal_variable_set.end()
/*|| internal_variable_set.find((entry1->second)[1]) == internal_variable_set.end()*/
) {
entry1InScope = false;
} else {
entry1InScope = true;
}
}
bool entry2InScope;
if (entry2 == varForBreakConcat.end()) {
entry2InScope = false;
} else {
if (internal_variable_set.find((entry2->second)[0]) == internal_variable_set.end()
/*|| internal_variable_set.find((entry2->second)[1]) == internal_variable_set.end()*/
) {
entry2InScope = false;
} else {
entry2InScope = true;
}
}
TRACE("str", tout << "entry 1 " << (entry1InScope ? "in scope" : "not in scope") << std::endl
<< "entry 2 " << (entry2InScope ? "in scope" : "not in scope") << std::endl;);
if (!entry1InScope && !entry2InScope) {
temp1 = mk_nonempty_str_var();
xorFlag = mk_internal_xor_var();
varForBreakConcat[key1][0] = temp1;
varForBreakConcat[key1][1] = xorFlag;
} else {
if (entry1InScope) {
temp1 = varForBreakConcat[key1][0];
xorFlag = varForBreakConcat[key1][1];
} else if (entry2InScope) {
temp1 = varForBreakConcat[key2][0];
xorFlag = varForBreakConcat[key2][1];
}
refresh_theory_var(temp1);
add_nonempty_constraint(temp1);
}
int splitType = -1;
if (x_len_exists && m_len_exists) {
if (x_len < m_len)
splitType = 0;
else if (x_len == m_len)
splitType = 1;
else
splitType = 2;
}
if (splitType == -1 && y_len_exists && str_len_exists) {
if (y_len > str_len)
splitType = 0;
else if (y_len == str_len)
splitType = 1;
else
splitType = 2;
}
TRACE("str", tout << "Split type " << splitType << std::endl;);
// Provide fewer split options when length information is available.
if (splitType == 0) {
// M cuts Y
// | x | y |
// | m | str |
expr_ref temp1_strAst(mk_concat(temp1, strAst), mgr);
if (can_two_nodes_eq(y, temp1_strAst)) {
expr_ref_vector l_items(mgr);
l_items.push_back(ctx.mk_eq_atom(concatAst1, concatAst2));
expr_ref_vector r_items(mgr);
expr_ref x_temp1(mk_concat(x, temp1), mgr);
r_items.push_back(ctx.mk_eq_atom(m, x_temp1));
r_items.push_back(ctx.mk_eq_atom(y, temp1_strAst));
if (x_len_exists && m_len_exists) {
l_items.push_back(ctx.mk_eq_atom(mk_strlen(x), mk_int(x_len)));
l_items.push_back(ctx.mk_eq_atom(mk_strlen(m), mk_int(m_len)));
rational m_sub_x = (m_len - x_len);
r_items.push_back(ctx.mk_eq_atom(mk_strlen(temp1), mk_int(m_sub_x)));
} else {
l_items.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_int(y_len)));
l_items.push_back(ctx.mk_eq_atom(mk_strlen(strAst), mk_int(str_len)));
rational y_sub_str = (y_len - str_len);
r_items.push_back(ctx.mk_eq_atom(mk_strlen(temp1), mk_int(y_sub_str)));
}
expr_ref ax_l(mk_and(l_items), mgr);
expr_ref ax_r(mk_and(r_items), mgr);
if (!avoidLoopCut || !(has_self_cut(m, y))) {
// break down option 2-1
add_cut_info_merge(temp1, sLevel, y);
add_cut_info_merge(temp1, sLevel, m);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(ax_l, ax_r), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ax_l, ax_r);
}
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
assert_implication(ax_l, tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIP" << std::endl;);
TRACE("str", {print_cut_var(m, tout); print_cut_var(y, tout);});
if (!overlapAssumptionUsed) {
overlapAssumptionUsed = true;
assert_implication(ax_l, m_theoryStrOverlapAssumption_term);
}
}
}
}
} else if (splitType == 1) {
// | x | y |
// | m | str |
expr_ref ax_l1(ctx.mk_eq_atom(concatAst1, concatAst2), mgr);
expr_ref ax_l2(mgr.mk_or(
ctx.mk_eq_atom(mk_strlen(x), mk_strlen(m)),
ctx.mk_eq_atom(mk_strlen(y), mk_strlen(strAst))), mgr);
expr_ref ax_l(mgr.mk_and(ax_l1, ax_l2), mgr);
expr_ref ax_r(mgr.mk_and(ctx.mk_eq_atom(x, m), ctx.mk_eq_atom(y, strAst)), mgr);
assert_implication(ax_l, ax_r);
} else if (splitType == 2) {
// m cut y,
// | x | y |
// | m | str |
rational lenDelta;
expr_ref_vector l_items(mgr);
l_items.push_back(ctx.mk_eq_atom(concatAst1, concatAst2));
if (x_len_exists && m_len_exists) {
l_items.push_back(ctx.mk_eq_atom(mk_strlen(x), mk_int(x_len)));
l_items.push_back(ctx.mk_eq_atom(mk_strlen(m), mk_int(m_len)));
lenDelta = x_len - m_len;
} else {
l_items.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_int(y_len)));
lenDelta = str_len - y_len;
}
TRACE("str",
tout
<< "xLen? " << (x_len_exists ? "yes" : "no") << std::endl
<< "mLen? " << (m_len_exists ? "yes" : "no") << std::endl
<< "yLen? " << (y_len_exists ? "yes" : "no") << std::endl
<< "xLen = " << x_len.to_string() << std::endl
<< "yLen = " << y_len.to_string() << std::endl
<< "mLen = " << m_len.to_string() << std::endl
<< "strLen = " << str_len.to_string() << std::endl
<< "lenDelta = " << lenDelta.to_string() << std::endl
<< "strValue = \"" << strValue << "\" (len=" << strValue.length() << ")" << "\n"
;
);
zstring part1Str = strValue.extract(0, lenDelta.get_unsigned());
zstring part2Str = strValue.extract(lenDelta.get_unsigned(), strValue.length() - lenDelta.get_unsigned());
expr_ref prefixStr(mk_string(part1Str), mgr);
expr_ref x_concat(mk_concat(m, prefixStr), mgr);
expr_ref cropStr(mk_string(part2Str), mgr);
if (can_two_nodes_eq(x, x_concat) && can_two_nodes_eq(y, cropStr)) {
expr_ref_vector r_items(mgr);
r_items.push_back(ctx.mk_eq_atom(x, x_concat));
r_items.push_back(ctx.mk_eq_atom(y, cropStr));
expr_ref ax_l(mk_and(l_items), mgr);
expr_ref ax_r(mk_and(r_items), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(ax_l, ax_r), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ax_l, ax_r);
}
} else {
// negate! It's impossible to split str with these lengths
TRACE("str", tout << "CONFLICT: Impossible to split str with these lengths." << std::endl;);
expr_ref ax_l(mk_and(l_items), mgr);
assert_axiom(mgr.mk_not(ax_l));
}
} else {
// Split type -1: no idea about the length...
expr_ref_vector arrangement_disjunction(mgr);
expr_ref temp1_strAst(mk_concat(temp1, strAst), mgr);
// m cuts y
if (can_two_nodes_eq(y, temp1_strAst)) {
if (!avoidLoopCut || !has_self_cut(m, y)) {
// break down option 2-1
expr_ref_vector and_item(mgr);
expr_ref x_temp1(mk_concat(x, temp1), mgr);
and_item.push_back(ctx.mk_eq_atom(m, x_temp1));
and_item.push_back(ctx.mk_eq_atom(y, temp1_strAst));
and_item.push_back(ctx.mk_eq_atom(mk_strlen(m),
m_autil.mk_add(mk_strlen(x), mk_strlen(temp1))));
expr_ref option1(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option1);
add_theory_aware_branching_info(option1, 0.1, l_true);
add_cut_info_merge(temp1, ctx.get_scope_level(), y);
add_cut_info_merge(temp1, ctx.get_scope_level(), m);
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
arrangement_disjunction.push_back(tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIPPED" << std::endl;);
TRACE("str", {print_cut_var(m, tout); print_cut_var(y, tout);});
if (!overlapAssumptionUsed) {
overlapAssumptionUsed = true;
arrangement_disjunction.push_back(m_theoryStrOverlapAssumption_term);
}
}
}
}
for (unsigned int i = 0; i <= strValue.length(); ++i) {
zstring part1Str = strValue.extract(0, i);
zstring part2Str = strValue.extract(i, strValue.length() - i);
expr_ref prefixStr(mk_string(part1Str), mgr);
expr_ref x_concat(mk_concat(m, prefixStr), mgr);
expr_ref cropStr(mk_string(part2Str), mgr);
if (can_two_nodes_eq(x, x_concat) && can_two_nodes_eq(y, cropStr)) {
// break down option 2-2
expr_ref_vector and_item(mgr);
and_item.push_back(ctx.mk_eq_atom(x, x_concat));
and_item.push_back(ctx.mk_eq_atom(y, cropStr));
and_item.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_int(part2Str.length())));
expr_ref option2(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option2);
double priority;
// prioritize the option where y is equal to the original string
if (i == 0) {
priority = 0.5;
} else {
priority = 0.1;
}
add_theory_aware_branching_info(option2, priority, l_true);
}
}
if (!arrangement_disjunction.empty()) {
expr_ref implyR(mk_or(arrangement_disjunction), mgr);
if (m_params.m_StrongArrangements) {
expr_ref implyLHS(ctx.mk_eq_atom(concatAst1, concatAst2), mgr);
expr_ref ax_strong(ctx.mk_eq_atom(implyLHS, implyR), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
generate_mutual_exclusion(arrangement_disjunction);
} else {
TRACE("str", tout << "STOP: Should not split two EQ concats." << std::endl;);
}
} // (splitType == -1)
}
/*************************************************************
* Type 3: concat(x, y) = concat("str", n)
*************************************************************/
bool theory_str::is_concat_eq_type3(expr * concatAst1, expr * concatAst2) {
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
if (u.str.is_string(v1_arg0) && (!u.str.is_string(v1_arg1))
&& (!u.str.is_string(v2_arg0)) && (!u.str.is_string(v2_arg1))) {
return true;
} else if (u.str.is_string(v2_arg0) && (!u.str.is_string(v2_arg1))
&& (!u.str.is_string(v1_arg0)) && (!u.str.is_string(v1_arg1))) {
return true;
} else {
return false;
}
}
void theory_str::process_concat_eq_type3(expr * concatAst1, expr * concatAst2) {
ast_manager & mgr = get_manager();
context & ctx = get_context();
bool overlapAssumptionUsed = false;
TRACE("str", tout << "process_concat_eq TYPE 3" << std::endl
<< "concatAst1 = " << mk_ismt2_pp(concatAst1, mgr) << std::endl
<< "concatAst2 = " << mk_ismt2_pp(concatAst2, mgr) << std::endl;
);
if (!u.str.is_concat(to_app(concatAst1))) {
TRACE("str", tout << "concatAst1 is not a concat function" << std::endl;);
return;
}
if (!u.str.is_concat(to_app(concatAst2))) {
TRACE("str", tout << "concatAst2 is not a concat function" << std::endl;);
return;
}
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
expr * x = NULL;
expr * y = NULL;
expr * strAst = NULL;
expr * n = NULL;
if (u.str.is_string(v1_arg0) && !u.str.is_string(v2_arg0)) {
strAst = v1_arg0;
n = v1_arg1;
x = v2_arg0;
y = v2_arg1;
} else {
strAst = v2_arg0;
n = v2_arg1;
x = v1_arg0;
y = v1_arg1;
}
zstring strValue;
u.str.is_string(strAst, strValue);
rational x_len, y_len, str_len, n_len;
bool x_len_exists = get_len_value(x, x_len);
bool y_len_exists = get_len_value(y, y_len);
str_len = rational((unsigned)(strValue.length()));
bool n_len_exists = get_len_value(n, n_len);
expr_ref xorFlag(mgr);
expr_ref temp1(mgr);
std::pair<expr*, expr*> key1(concatAst1, concatAst2);
std::pair<expr*, expr*> key2(concatAst2, concatAst1);
// check the entries in this map to make sure they're still in scope
// before we use them.
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry1 = varForBreakConcat.find(key1);
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry2 = varForBreakConcat.find(key2);
bool entry1InScope;
if (entry1 == varForBreakConcat.end()) {
entry1InScope = false;
} else {
if (internal_variable_set.find((entry1->second)[0]) == internal_variable_set.end()
/* || internal_variable_set.find((entry1->second)[1]) == internal_variable_set.end() */) {
entry1InScope = false;
} else {
entry1InScope = true;
}
}
bool entry2InScope;
if (entry2 == varForBreakConcat.end()) {
entry2InScope = false;
} else {
if (internal_variable_set.find((entry2->second)[0]) == internal_variable_set.end()
/* || internal_variable_set.find((entry2->second)[1]) == internal_variable_set.end() */) {
entry2InScope = false;
} else {
entry2InScope = true;
}
}
TRACE("str", tout << "entry 1 " << (entry1InScope ? "in scope" : "not in scope") << std::endl
<< "entry 2 " << (entry2InScope ? "in scope" : "not in scope") << std::endl;);
if (!entry1InScope && !entry2InScope) {
temp1 = mk_nonempty_str_var();
xorFlag = mk_internal_xor_var();
varForBreakConcat[key1][0] = temp1;
varForBreakConcat[key1][1] = xorFlag;
} else {
if (entry1InScope) {
temp1 = varForBreakConcat[key1][0];
xorFlag = varForBreakConcat[key1][1];
} else if (varForBreakConcat.find(key2) != varForBreakConcat.end()) {
temp1 = varForBreakConcat[key2][0];
xorFlag = varForBreakConcat[key2][1];
}
refresh_theory_var(temp1);
add_nonempty_constraint(temp1);
}
int splitType = -1;
if (x_len_exists) {
if (x_len < str_len)
splitType = 0;
else if (x_len == str_len)
splitType = 1;
else
splitType = 2;
}
if (splitType == -1 && y_len_exists && n_len_exists) {
if (y_len > n_len)
splitType = 0;
else if (y_len == n_len)
splitType = 1;
else
splitType = 2;
}
TRACE("str", tout << "Split type " << splitType << std::endl;);
// Provide fewer split options when length information is available.
if (splitType == 0) {
// | x | y |
// | str | n |
expr_ref_vector litems(mgr);
litems.push_back(ctx.mk_eq_atom(concatAst1, concatAst2));
rational prefixLen;
if (!x_len_exists) {
prefixLen = str_len - (y_len - n_len);
litems.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_int(y_len)));
litems.push_back(ctx.mk_eq_atom(mk_strlen(n), mk_int(n_len)));
} else {
prefixLen = x_len;
litems.push_back(ctx.mk_eq_atom(mk_strlen(x), mk_int(x_len)));
}
zstring prefixStr = strValue.extract(0, prefixLen.get_unsigned());
rational str_sub_prefix = str_len - prefixLen;
zstring suffixStr = strValue.extract(prefixLen.get_unsigned(), str_sub_prefix.get_unsigned());
expr_ref prefixAst(mk_string(prefixStr), mgr);
expr_ref suffixAst(mk_string(suffixStr), mgr);
expr_ref ax_l(mgr.mk_and(litems.size(), litems.c_ptr()), mgr);
expr_ref suf_n_concat(mk_concat(suffixAst, n), mgr);
if (can_two_nodes_eq(x, prefixAst) && can_two_nodes_eq(y, suf_n_concat)) {
expr_ref_vector r_items(mgr);
r_items.push_back(ctx.mk_eq_atom(x, prefixAst));
r_items.push_back(ctx.mk_eq_atom(y, suf_n_concat));
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(ax_l, mk_and(r_items)), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ax_l, mk_and(r_items));
}
} else {
// negate! It's impossible to split str with these lengths
TRACE("str", tout << "CONFLICT: Impossible to split str with these lengths." << std::endl;);
assert_axiom(mgr.mk_not(ax_l));
}
}
else if (splitType == 1) {
expr_ref ax_l1(ctx.mk_eq_atom(concatAst1, concatAst2), mgr);
expr_ref ax_l2(mgr.mk_or(
ctx.mk_eq_atom(mk_strlen(x), mk_strlen(strAst)),
ctx.mk_eq_atom(mk_strlen(y), mk_strlen(n))), mgr);
expr_ref ax_l(mgr.mk_and(ax_l1, ax_l2), mgr);
expr_ref ax_r(mgr.mk_and(ctx.mk_eq_atom(x, strAst), ctx.mk_eq_atom(y, n)), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(ax_l, ax_r), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ax_l, ax_r);
}
}
else if (splitType == 2) {
// | x | y |
// | str | n |
expr_ref_vector litems(mgr);
litems.push_back(ctx.mk_eq_atom(concatAst1, concatAst2));
rational tmpLen;
if (!x_len_exists) {
tmpLen = n_len - y_len;
litems.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_int(y_len)));
litems.push_back(ctx.mk_eq_atom(mk_strlen(n), mk_int(n_len)));
} else {
tmpLen = x_len - str_len;
litems.push_back(ctx.mk_eq_atom(mk_strlen(x), mk_int(x_len)));
}
expr_ref ax_l(mgr.mk_and(litems.size(), litems.c_ptr()), mgr);
expr_ref str_temp1(mk_concat(strAst, temp1), mgr);
expr_ref temp1_y(mk_concat(temp1, y), mgr);
if (can_two_nodes_eq(x, str_temp1)) {
if (!avoidLoopCut || !(has_self_cut(x, n))) {
expr_ref_vector r_items(mgr);
r_items.push_back(ctx.mk_eq_atom(x, str_temp1));
r_items.push_back(ctx.mk_eq_atom(n, temp1_y));
r_items.push_back(ctx.mk_eq_atom(mk_strlen(temp1), mk_int(tmpLen)));
expr_ref ax_r(mk_and(r_items), mgr);
//Cut Info
add_cut_info_merge(temp1, sLevel, x);
add_cut_info_merge(temp1, sLevel, n);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(ax_l, ax_r), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ax_l, ax_r);
}
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
assert_implication(ax_l, tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIPPED" << std::endl;);
TRACE("str", {print_cut_var(x, tout); print_cut_var(n, tout);});
if (!overlapAssumptionUsed) {
overlapAssumptionUsed = true;
assert_implication(ax_l, m_theoryStrOverlapAssumption_term);
}
}
}
}
// else {
// // negate! It's impossible to split str with these lengths
// __debugPrint(logFile, "[Conflict] Negate! It's impossible to split str with these lengths @ %d.\n", __LINE__);
// addAxiom(t, Z3_mk_not(ctx, ax_l), __LINE__);
// }
}
else {
// Split type -1. We know nothing about the length...
expr_ref_vector arrangement_disjunction(mgr);
int pos = 1;
for (unsigned int i = 0; i <= strValue.length(); i++) {
zstring part1Str = strValue.extract(0, i);
zstring part2Str = strValue.extract(i, strValue.length() - i);
expr_ref cropStr(mk_string(part1Str), mgr);
expr_ref suffixStr(mk_string(part2Str), mgr);
expr_ref y_concat(mk_concat(suffixStr, n), mgr);
if (can_two_nodes_eq(x, cropStr) && can_two_nodes_eq(y, y_concat)) {
expr_ref_vector and_item(mgr);
// break down option 3-1
expr_ref x_eq_str(ctx.mk_eq_atom(x, cropStr), mgr);
and_item.push_back(x_eq_str); ++pos;
and_item.push_back(ctx.mk_eq_atom(y, y_concat));
and_item.push_back(ctx.mk_eq_atom(mk_strlen(x), mk_strlen(cropStr))); ++pos;
// and_item[pos++] = Z3_mk_eq(ctx, or_item[option], Z3_mk_eq(ctx, mk_length(t, y), mk_length(t, y_concat)));
// adding length constraint for _ = constStr seems slowing things down.
expr_ref option1(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option1);
double priority;
if (i == strValue.length()) {
priority = 0.5;
} else {
priority = 0.1;
}
add_theory_aware_branching_info(option1, priority, l_true);
}
}
expr_ref strAst_temp1(mk_concat(strAst, temp1), mgr);
//--------------------------------------------------------
// x cut n
//--------------------------------------------------------
if (can_two_nodes_eq(x, strAst_temp1)) {
if (!avoidLoopCut || !(has_self_cut(x, n))) {
// break down option 3-2
expr_ref_vector and_item(mgr);
expr_ref temp1_y(mk_concat(temp1, y), mgr);
and_item.push_back(ctx.mk_eq_atom(x, strAst_temp1)); ++pos;
and_item.push_back(ctx.mk_eq_atom(n, temp1_y)); ++pos;
and_item.push_back(ctx.mk_eq_atom(mk_strlen(x),
m_autil.mk_add(mk_strlen(strAst), mk_strlen(temp1)) ) ); ++pos;
expr_ref option2(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option2);
add_theory_aware_branching_info(option2, 0.1, l_true);
add_cut_info_merge(temp1, sLevel, x);
add_cut_info_merge(temp1, sLevel, n);
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
arrangement_disjunction.push_back(tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIPPED." << std::endl;);
TRACE("str", {print_cut_var(x, tout); print_cut_var(n, tout);});
if (!overlapAssumptionUsed) {
overlapAssumptionUsed = true;
arrangement_disjunction.push_back(m_theoryStrOverlapAssumption_term);
}
}
}
}
if (!arrangement_disjunction.empty()) {
expr_ref implyR(mk_or(arrangement_disjunction), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_lhs(ctx.mk_eq_atom(concatAst1, concatAst2), mgr);
expr_ref ax_strong(ctx.mk_eq_atom(ax_lhs, implyR), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
generate_mutual_exclusion(arrangement_disjunction);
} else {
TRACE("str", tout << "STOP: should not split two eq. concats" << std::endl;);
}
}
}
/*************************************************************
* Type 4: concat("str1", y) = concat("str2", n)
*************************************************************/
bool theory_str::is_concat_eq_type4(expr * concatAst1, expr * concatAst2) {
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
if (u.str.is_string(v1_arg0) && (!u.str.is_string(v1_arg1))
&& u.str.is_string(v2_arg0) && (!u.str.is_string(v2_arg1))) {
return true;
} else {
return false;
}
}
void theory_str::process_concat_eq_type4(expr * concatAst1, expr * concatAst2) {
ast_manager & mgr = get_manager();
context & ctx = get_context();
TRACE("str", tout << "process_concat_eq TYPE 4" << std::endl
<< "concatAst1 = " << mk_ismt2_pp(concatAst1, mgr) << std::endl
<< "concatAst2 = " << mk_ismt2_pp(concatAst2, mgr) << std::endl;
);
if (!u.str.is_concat(to_app(concatAst1))) {
TRACE("str", tout << "concatAst1 is not a concat function" << std::endl;);
return;
}
if (!u.str.is_concat(to_app(concatAst2))) {
TRACE("str", tout << "concatAst2 is not a concat function" << std::endl;);
return;
}
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
expr * str1Ast = v1_arg0;
expr * y = v1_arg1;
expr * str2Ast = v2_arg0;
expr * n = v2_arg1;
zstring str1Value, str2Value;
u.str.is_string(str1Ast, str1Value);
u.str.is_string(str2Ast, str2Value);
unsigned int str1Len = str1Value.length();
unsigned int str2Len = str2Value.length();
int commonLen = (str1Len > str2Len) ? str2Len : str1Len;
if (str1Value.extract(0, commonLen) != str2Value.extract(0, commonLen)) {
TRACE("str", tout << "Conflict: " << mk_ismt2_pp(concatAst1, mgr)
<< " has no common prefix with " << mk_ismt2_pp(concatAst2, mgr) << std::endl;);
expr_ref toNegate(mgr.mk_not(ctx.mk_eq_atom(concatAst1, concatAst2)), mgr);
assert_axiom(toNegate);
return;
} else {
if (str1Len > str2Len) {
zstring deltaStr = str1Value.extract(str2Len, str1Len - str2Len);
expr_ref tmpAst(mk_concat(mk_string(deltaStr), y), mgr);
if (!in_same_eqc(tmpAst, n)) {
// break down option 4-1
expr_ref implyR(ctx.mk_eq_atom(n, tmpAst), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom( ctx.mk_eq_atom(concatAst1, concatAst2), implyR ), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
}
} else if (str1Len == str2Len) {
if (!in_same_eqc(n, y)) {
//break down option 4-2
expr_ref implyR(ctx.mk_eq_atom(n, y), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom( ctx.mk_eq_atom(concatAst1, concatAst2), implyR ), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
}
} else {
zstring deltaStr = str2Value.extract(str1Len, str2Len - str1Len);
expr_ref tmpAst(mk_concat(mk_string(deltaStr), n), mgr);
if (!in_same_eqc(y, tmpAst)) {
//break down option 4-3
expr_ref implyR(ctx.mk_eq_atom(y, tmpAst), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom( ctx.mk_eq_atom(concatAst1, concatAst2), implyR ), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
}
}
}
}
/*************************************************************
* case 5: concat(x, "str1") = concat(m, "str2")
*************************************************************/
bool theory_str::is_concat_eq_type5(expr * concatAst1, expr * concatAst2) {
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
if ((!u.str.is_string(v1_arg0)) && u.str.is_string(v1_arg1)
&& (!u.str.is_string(v2_arg0)) && u.str.is_string(v2_arg1)) {
return true;
} else {
return false;
}
}
void theory_str::process_concat_eq_type5(expr * concatAst1, expr * concatAst2) {
ast_manager & mgr = get_manager();
context & ctx = get_context();
TRACE("str", tout << "process_concat_eq TYPE 5" << std::endl
<< "concatAst1 = " << mk_ismt2_pp(concatAst1, mgr) << std::endl
<< "concatAst2 = " << mk_ismt2_pp(concatAst2, mgr) << std::endl;
);
if (!u.str.is_concat(to_app(concatAst1))) {
TRACE("str", tout << "concatAst1 is not a concat function" << std::endl;);
return;
}
if (!u.str.is_concat(to_app(concatAst2))) {
TRACE("str", tout << "concatAst2 is not a concat function" << std::endl;);
return;
}
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
expr * x = v1_arg0;
expr * str1Ast = v1_arg1;
expr * m = v2_arg0;
expr * str2Ast = v2_arg1;
zstring str1Value, str2Value;
u.str.is_string(str1Ast, str1Value);
u.str.is_string(str2Ast, str2Value);
unsigned int str1Len = str1Value.length();
unsigned int str2Len = str2Value.length();
int cLen = (str1Len > str2Len) ? str2Len : str1Len;
if (str1Value.extract(str1Len - cLen, cLen) != str2Value.extract(str2Len - cLen, cLen)) {
TRACE("str", tout << "Conflict: " << mk_ismt2_pp(concatAst1, mgr)
<< " has no common suffix with " << mk_ismt2_pp(concatAst2, mgr) << std::endl;);
expr_ref toNegate(mgr.mk_not(ctx.mk_eq_atom(concatAst1, concatAst2)), mgr);
assert_axiom(toNegate);
return;
} else {
if (str1Len > str2Len) {
zstring deltaStr = str1Value.extract(0, str1Len - str2Len);
expr_ref x_deltaStr(mk_concat(x, mk_string(deltaStr)), mgr);
if (!in_same_eqc(m, x_deltaStr)) {
expr_ref implyR(ctx.mk_eq_atom(m, x_deltaStr), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom( ctx.mk_eq_atom(concatAst1, concatAst2), implyR ), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
}
} else if (str1Len == str2Len) {
// test
if (!in_same_eqc(x, m)) {
expr_ref implyR(ctx.mk_eq_atom(x, m), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom( ctx.mk_eq_atom(concatAst1, concatAst2), implyR ), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
}
} else {
zstring deltaStr = str2Value.extract(0, str2Len - str1Len);
expr_ref m_deltaStr(mk_concat(m, mk_string(deltaStr)), mgr);
if (!in_same_eqc(x, m_deltaStr)) {
expr_ref implyR(ctx.mk_eq_atom(x, m_deltaStr), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom( ctx.mk_eq_atom(concatAst1, concatAst2), implyR ), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
}
}
}
}
/*************************************************************
* case 6: concat("str1", y) = concat(m, "str2")
*************************************************************/
bool theory_str::is_concat_eq_type6(expr * concatAst1, expr * concatAst2) {
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
if (u.str.is_string(v1_arg0) && (!u.str.is_string(v1_arg1))
&& (!u.str.is_string(v2_arg0)) && u.str.is_string(v2_arg1)) {
return true;
} else if (u.str.is_string(v2_arg0) && (!u.str.is_string(v2_arg1))
&& (!u.str.is_string(v1_arg0)) && u.str.is_string(v1_arg1)) {
return true;
} else {
return false;
}
}
void theory_str::process_concat_eq_type6(expr * concatAst1, expr * concatAst2) {
ast_manager & mgr = get_manager();
context & ctx = get_context();
TRACE("str", tout << "process_concat_eq TYPE 6" << std::endl
<< "concatAst1 = " << mk_ismt2_pp(concatAst1, mgr) << std::endl
<< "concatAst2 = " << mk_ismt2_pp(concatAst2, mgr) << std::endl;
);
if (!u.str.is_concat(to_app(concatAst1))) {
TRACE("str", tout << "concatAst1 is not a concat function" << std::endl;);
return;
}
if (!u.str.is_concat(to_app(concatAst2))) {
TRACE("str", tout << "concatAst2 is not a concat function" << std::endl;);
return;
}
expr * v1_arg0 = to_app(concatAst1)->get_arg(0);
expr * v1_arg1 = to_app(concatAst1)->get_arg(1);
expr * v2_arg0 = to_app(concatAst2)->get_arg(0);
expr * v2_arg1 = to_app(concatAst2)->get_arg(1);
expr * str1Ast = NULL;
expr * y = NULL;
expr * m = NULL;
expr * str2Ast = NULL;
if (u.str.is_string(v1_arg0)) {
str1Ast = v1_arg0;
y = v1_arg1;
m = v2_arg0;
str2Ast = v2_arg1;
} else {
str1Ast = v2_arg0;
y = v2_arg1;
m = v1_arg0;
str2Ast = v1_arg1;
}
zstring str1Value, str2Value;
u.str.is_string(str1Ast, str1Value);
u.str.is_string(str2Ast, str2Value);
unsigned int str1Len = str1Value.length();
unsigned int str2Len = str2Value.length();
//----------------------------------------
//(a) |---str1---|----y----|
// |--m--|-----str2-----|
//
//(b) |---str1---|----y----|
// |-----m----|--str2---|
//
//(c) |---str1---|----y----|
// |------m------|-str2-|
//----------------------------------------
std::list<unsigned int> overlapLen;
overlapLen.push_back(0);
for (unsigned int i = 1; i <= str1Len && i <= str2Len; i++) {
if (str1Value.extract(str1Len - i, i) == str2Value.extract(0, i))
overlapLen.push_back(i);
}
//----------------------------------------------------------------
expr * commonVar = NULL;
expr * xorFlag = NULL;
std::pair<expr*, expr*> key1(concatAst1, concatAst2);
std::pair<expr*, expr*> key2(concatAst2, concatAst1);
// check the entries in this map to make sure they're still in scope
// before we use them.
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry1 = varForBreakConcat.find(key1);
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry2 = varForBreakConcat.find(key2);
bool entry1InScope;
if (entry1 == varForBreakConcat.end()) {
entry1InScope = false;
} else {
if (internal_variable_set.find((entry1->second)[0]) == internal_variable_set.end()
/* || internal_variable_set.find((entry1->second)[1]) == internal_variable_set.end() */) {
entry1InScope = false;
} else {
entry1InScope = true;
}
}
bool entry2InScope;
if (entry2 == varForBreakConcat.end()) {
entry2InScope = false;
} else {
if (internal_variable_set.find((entry2->second)[0]) == internal_variable_set.end()
/* || internal_variable_set.find((entry2->second)[1]) == internal_variable_set.end() */) {
entry2InScope = false;
} else {
entry2InScope = true;
}
}
TRACE("str", tout << "entry 1 " << (entry1InScope ? "in scope" : "not in scope") << std::endl
<< "entry 2 " << (entry2InScope ? "in scope" : "not in scope") << std::endl;);
if (!entry1InScope && !entry2InScope) {
commonVar = mk_nonempty_str_var();
xorFlag = mk_internal_xor_var();
varForBreakConcat[key1][0] = commonVar;
varForBreakConcat[key1][1] = xorFlag;
} else {
if (entry1InScope) {
commonVar = (entry1->second)[0];
xorFlag = (entry1->second)[1];
} else {
commonVar = (entry2->second)[0];
xorFlag = (entry2->second)[1];
}
refresh_theory_var(commonVar);
add_nonempty_constraint(commonVar);
}
bool overlapAssumptionUsed = false;
expr_ref_vector arrangement_disjunction(mgr);
int pos = 1;
if (!avoidLoopCut || !has_self_cut(m, y)) {
expr_ref_vector and_item(mgr);
expr_ref str1_commonVar(mk_concat(str1Ast, commonVar), mgr);
and_item.push_back(ctx.mk_eq_atom(m, str1_commonVar));
pos += 1;
expr_ref commonVar_str2(mk_concat(commonVar, str2Ast), mgr);
and_item.push_back(ctx.mk_eq_atom(y, commonVar_str2));
pos += 1;
and_item.push_back(ctx.mk_eq_atom(mk_strlen(m),
m_autil.mk_add(mk_strlen(str1Ast), mk_strlen(commonVar)) ));
pos += 1;
// addItems[0] = mk_length(t, commonVar);
// addItems[1] = mk_length(t, str2Ast);
// and_item[pos++] = Z3_mk_eq(ctx, or_item[option], Z3_mk_eq(ctx, mk_length(t, y), Z3_mk_add(ctx, 2, addItems)));
expr_ref option1(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option1);
add_theory_aware_branching_info(option1, 0.1, l_true);
} else {
loopDetected = true;
if (m_params.m_FiniteOverlapModels) {
expr_ref tester = set_up_finite_model_test(concatAst1, concatAst2);
arrangement_disjunction.push_back(tester);
add_theory_aware_branching_info(tester, m_params.m_OverlapTheoryAwarePriority, l_true);
} else {
TRACE("str", tout << "AVOID LOOP: SKIPPED." << std::endl;);
TRACE("str", print_cut_var(m, tout); print_cut_var(y, tout););
// only add the overlap assumption one time
if (!overlapAssumptionUsed) {
arrangement_disjunction.push_back(m_theoryStrOverlapAssumption_term);
overlapAssumptionUsed = true;
}
}
}
for (std::list<unsigned int>::iterator itor = overlapLen.begin(); itor != overlapLen.end(); itor++) {
unsigned int overLen = *itor;
zstring prefix = str1Value.extract(0, str1Len - overLen);
zstring suffix = str2Value.extract(overLen, str2Len - overLen);
expr_ref_vector and_item(mgr);
expr_ref prefixAst(mk_string(prefix), mgr);
expr_ref x_eq_prefix(ctx.mk_eq_atom(m, prefixAst), mgr);
and_item.push_back(x_eq_prefix);
pos += 1;
and_item.push_back(
ctx.mk_eq_atom(mk_strlen(m), mk_strlen(prefixAst)));
pos += 1;
// adding length constraint for _ = constStr seems slowing things down.
expr_ref suffixAst(mk_string(suffix), mgr);
expr_ref y_eq_suffix(ctx.mk_eq_atom(y, suffixAst), mgr);
and_item.push_back(y_eq_suffix);
pos += 1;
and_item.push_back(ctx.mk_eq_atom(mk_strlen(y), mk_strlen(suffixAst)));
pos += 1;
expr_ref option2(mk_and(and_item), mgr);
arrangement_disjunction.push_back(option2);
double priority;
// prefer the option "str1" = x
if (prefix == str1Value) {
priority = 0.5;
} else {
priority = 0.1;
}
add_theory_aware_branching_info(option2, priority, l_true);
}
// case 6: concat("str1", y) = concat(m, "str2")
expr_ref implyR(mk_or(arrangement_disjunction), mgr);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom( ctx.mk_eq_atom(concatAst1, concatAst2), implyR ), mgr);
assert_axiom(ax_strong);
} else {
assert_implication(ctx.mk_eq_atom(concatAst1, concatAst2), implyR);
}
generate_mutual_exclusion(arrangement_disjunction);
}
void theory_str::process_unroll_eq_const_str(expr * unrollFunc, expr * constStr) {
ast_manager & m = get_manager();
if (!u.re.is_unroll(to_app(unrollFunc))) {
return;
}
if (!u.str.is_string(constStr)) {
return;
}
expr * funcInUnroll = to_app(unrollFunc)->get_arg(0);
zstring strValue;
u.str.is_string(constStr, strValue);
TRACE("str", tout << "unrollFunc: " << mk_pp(unrollFunc, m) << std::endl
<< "constStr: " << mk_pp(constStr, m) << std::endl;);
if (strValue == "") {
return;
}
if (u.re.is_to_re(to_app(funcInUnroll))) {
unroll_str2reg_constStr(unrollFunc, constStr);
return;
}
}
void theory_str::process_concat_eq_unroll(expr * concat, expr * unroll) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
TRACE("str", tout << "concat = " << mk_pp(concat, mgr) << ", unroll = " << mk_pp(unroll, mgr) << std::endl;);
std::pair<expr*, expr*> key = std::make_pair(concat, unroll);
expr_ref toAssert(mgr);
if (concat_eq_unroll_ast_map.find(key) == concat_eq_unroll_ast_map.end()) {
expr_ref arg1(to_app(concat)->get_arg(0), mgr);
expr_ref arg2(to_app(concat)->get_arg(1), mgr);
expr_ref r1(to_app(unroll)->get_arg(0), mgr);
expr_ref t1(to_app(unroll)->get_arg(1), mgr);
expr_ref v1(mk_regex_rep_var(), mgr);
expr_ref v2(mk_regex_rep_var(), mgr);
expr_ref v3(mk_regex_rep_var(), mgr);
expr_ref v4(mk_regex_rep_var(), mgr);
expr_ref v5(mk_regex_rep_var(), mgr);
expr_ref t2(mk_unroll_bound_var(), mgr);
expr_ref t3(mk_unroll_bound_var(), mgr);
expr_ref emptyStr(mk_string(""), mgr);
expr_ref unroll1(mk_unroll(r1, t2), mgr);
expr_ref unroll2(mk_unroll(r1, t3), mgr);
expr_ref op0(ctx.mk_eq_atom(t1, mk_int(0)), mgr);
expr_ref op1(m_autil.mk_ge(t1, mk_int(1)), mgr);
expr_ref_vector op1Items(mgr);
expr_ref_vector op2Items(mgr);
op1Items.push_back(ctx.mk_eq_atom(arg1, emptyStr));
op1Items.push_back(ctx.mk_eq_atom(arg2, emptyStr));
op1Items.push_back(ctx.mk_eq_atom(mk_strlen(arg1), mk_int(0)));
op1Items.push_back(ctx.mk_eq_atom(mk_strlen(arg2), mk_int(0)));
expr_ref opAnd1(ctx.mk_eq_atom(op0, mk_and(op1Items)), mgr);
expr_ref v1v2(mk_concat(v1, v2), mgr);
op2Items.push_back(ctx.mk_eq_atom(arg1, v1v2));
op2Items.push_back(ctx.mk_eq_atom(mk_strlen(arg1), m_autil.mk_add(mk_strlen(v1), mk_strlen(v2))));
expr_ref v3v4(mk_concat(v3, v4), mgr);
op2Items.push_back(ctx.mk_eq_atom(arg2, v3v4));
op2Items.push_back(ctx.mk_eq_atom(mk_strlen(arg2), m_autil.mk_add(mk_strlen(v3), mk_strlen(v4))));
op2Items.push_back(ctx.mk_eq_atom(v1, unroll1));
op2Items.push_back(ctx.mk_eq_atom(mk_strlen(v1), mk_strlen(unroll1)));
op2Items.push_back(ctx.mk_eq_atom(v4, unroll2));
op2Items.push_back(ctx.mk_eq_atom(mk_strlen(v4), mk_strlen(unroll2)));
expr_ref v2v3(mk_concat(v2, v3), mgr);
op2Items.push_back(ctx.mk_eq_atom(v5, v2v3));
reduce_virtual_regex_in(v5, r1, op2Items);
op2Items.push_back(ctx.mk_eq_atom(mk_strlen(v5), m_autil.mk_add(mk_strlen(v2), mk_strlen(v3))));
op2Items.push_back(ctx.mk_eq_atom(m_autil.mk_add(t2, t3), m_autil.mk_add(t1, mk_int(-1))));
expr_ref opAnd2(ctx.mk_eq_atom(op1, mk_and(op2Items)), mgr);
toAssert = mgr.mk_and(opAnd1, opAnd2);
m_trail.push_back(toAssert);
concat_eq_unroll_ast_map[key] = toAssert;
} else {
toAssert = concat_eq_unroll_ast_map[key];
}
assert_axiom(toAssert);
}
void theory_str::unroll_str2reg_constStr(expr * unrollFunc, expr * eqConstStr) {
context & ctx = get_context();
ast_manager & m = get_manager();
expr * str2RegFunc = to_app(unrollFunc)->get_arg(0);
expr * strInStr2RegFunc = to_app(str2RegFunc)->get_arg(0);
expr * oriCnt = to_app(unrollFunc)->get_arg(1);
zstring strValue;
u.str.is_string(eqConstStr, strValue);
zstring regStrValue;
u.str.is_string(strInStr2RegFunc, regStrValue);
unsigned int strLen = strValue.length();
unsigned int regStrLen = regStrValue.length();
SASSERT(regStrLen != 0); // this should never occur -- the case for empty string is handled elsewhere
unsigned int cnt = strLen / regStrLen;
expr_ref implyL(ctx.mk_eq_atom(unrollFunc, eqConstStr), m);
expr_ref implyR1(ctx.mk_eq_atom(oriCnt, mk_int(cnt)), m);
expr_ref implyR2(ctx.mk_eq_atom(mk_strlen(unrollFunc), mk_int(strLen)), m);
expr_ref axiomRHS(m.mk_and(implyR1, implyR2), m);
SASSERT(implyL);
SASSERT(axiomRHS);
assert_implication(implyL, axiomRHS);
}
/*
* Look through the equivalence class of n to find a string constant.
* Return that constant if it is found, and set hasEqcValue to true.
* Otherwise, return n, and set hasEqcValue to false.
*/
expr * theory_str::get_eqc_value(expr * n, bool & hasEqcValue) {
return z3str2_get_eqc_value(n, hasEqcValue);
}
// Simulate the behaviour of get_eqc_value() from Z3str2.
// We only check m_find for a string constant.
expr * theory_str::z3str2_get_eqc_value(expr * n , bool & hasEqcValue) {
expr * curr = n;
do {
if (u.str.is_string(curr)) {
hasEqcValue = true;
return curr;
}
curr = get_eqc_next(curr);
} while (curr != n);
hasEqcValue = false;
return n;
}
// from Z3: theory_seq.cpp
static theory_mi_arith* get_th_arith(context& ctx, theory_id afid, expr* e) {
theory* th = ctx.get_theory(afid);
if (th && ctx.e_internalized(e)) {
return dynamic_cast<theory_mi_arith*>(th);
}
else {
return 0;
}
}
bool theory_str::get_value(expr* e, rational& val) const {
if (opt_DisableIntegerTheoryIntegration) {
TRACE("str", tout << "WARNING: integer theory integration disabled" << std::endl;);
return false;
}
context& ctx = get_context();
ast_manager & m = get_manager();
theory_mi_arith* tha = get_th_arith(ctx, m_autil.get_family_id(), e);
if (!tha) {
return false;
}
TRACE("str", tout << "checking eqc of " << mk_pp(e, m) << " for arithmetic value" << std::endl;);
expr_ref _val(m);
enode * en_e = ctx.get_enode(e);
enode * it = en_e;
do {
if (m_autil.is_numeral(it->get_owner(), val) && val.is_int()) {
// found an arithmetic term
TRACE("str", tout << mk_pp(it->get_owner(), m) << " is an integer ( ~= " << val << " )"
<< std::endl;);
return true;
} else {
TRACE("str", tout << mk_pp(it->get_owner(), m) << " not a numeral" << std::endl;);
}
it = it->get_next();
} while (it != en_e);
TRACE("str", tout << "no arithmetic values found in eqc" << std::endl;);
return false;
}
bool theory_str::lower_bound(expr* _e, rational& lo) {
if (opt_DisableIntegerTheoryIntegration) {
TRACE("str", tout << "WARNING: integer theory integration disabled" << std::endl;);
return false;
}
context& ctx = get_context();
ast_manager & m = get_manager();
theory_mi_arith* tha = get_th_arith(ctx, m_autil.get_family_id(), _e);
expr_ref _lo(m);
if (!tha || !tha->get_lower(ctx.get_enode(_e), _lo)) return false;
return m_autil.is_numeral(_lo, lo) && lo.is_int();
}
bool theory_str::upper_bound(expr* _e, rational& hi) {
if (opt_DisableIntegerTheoryIntegration) {
TRACE("str", tout << "WARNING: integer theory integration disabled" << std::endl;);
return false;
}
context& ctx = get_context();
ast_manager & m = get_manager();
theory_mi_arith* tha = get_th_arith(ctx, m_autil.get_family_id(), _e);
expr_ref _hi(m);
if (!tha || !tha->get_upper(ctx.get_enode(_e), _hi)) return false;
return m_autil.is_numeral(_hi, hi) && hi.is_int();
}
bool theory_str::get_len_value(expr* e, rational& val) {
if (opt_DisableIntegerTheoryIntegration) {
TRACE("str", tout << "WARNING: integer theory integration disabled" << std::endl;);
return false;
}
context& ctx = get_context();
ast_manager & m = get_manager();
theory* th = ctx.get_theory(m_autil.get_family_id());
if (!th) {
TRACE("str", tout << "oops, can't get m_autil's theory" << std::endl;);
return false;
}
theory_mi_arith* tha = dynamic_cast<theory_mi_arith*>(th);
if (!tha) {
TRACE("str", tout << "oops, can't cast to theory_mi_arith" << std::endl;);
return false;
}
TRACE("str", tout << "checking len value of " << mk_ismt2_pp(e, m) << std::endl;);
rational val1;
expr_ref len(m), len_val(m);
expr* e1, *e2;
ptr_vector<expr> todo;
todo.push_back(e);
val.reset();
while (!todo.empty()) {
expr* c = todo.back();
todo.pop_back();
if (u.str.is_concat(to_app(c))) {
e1 = to_app(c)->get_arg(0);
e2 = to_app(c)->get_arg(1);
todo.push_back(e1);
todo.push_back(e2);
}
else if (u.str.is_string(to_app(c))) {
zstring tmp;
u.str.is_string(to_app(c), tmp);
unsigned int sl = tmp.length();
val += rational(sl);
}
else {
len = mk_strlen(c);
// debugging
TRACE("str", {
tout << mk_pp(len, m) << ":" << std::endl
<< (ctx.is_relevant(len.get()) ? "relevant" : "not relevant") << std::endl
<< (ctx.e_internalized(len) ? "internalized" : "not internalized") << std::endl
;
if (ctx.e_internalized(len)) {
enode * e_len = ctx.get_enode(len);
tout << "has " << e_len->get_num_th_vars() << " theory vars" << std::endl;
// eqc debugging
{
tout << "dump equivalence class of " << mk_pp(len, get_manager()) << std::endl;
enode * nNode = ctx.get_enode(len);
enode * eqcNode = nNode;
do {
app * ast = eqcNode->get_owner();
tout << mk_pp(ast, get_manager()) << std::endl;
eqcNode = eqcNode->get_next();
} while (eqcNode != nNode);
}
}
});
if (ctx.e_internalized(len) && get_value(len, val1)) {
val += val1;
TRACE("str", tout << "integer theory: subexpression " << mk_ismt2_pp(len, m) << " has length " << val1 << std::endl;);
}
else {
TRACE("str", tout << "integer theory: subexpression " << mk_ismt2_pp(len, m) << " has no length assignment; bailing out" << std::endl;);
return false;
}
}
}
TRACE("str", tout << "length of " << mk_ismt2_pp(e, m) << " is " << val << std::endl;);
return val.is_int();
}
/*
* Decide whether n1 and n2 are already in the same equivalence class.
* This only checks whether the core considers them to be equal;
* they may not actually be equal.
*/
bool theory_str::in_same_eqc(expr * n1, expr * n2) {
if (n1 == n2) return true;
context & ctx = get_context();
ast_manager & m = get_manager();
// similar to get_eqc_value(), make absolutely sure
// that we've set this up properly for the context
if (!ctx.e_internalized(n1)) {
TRACE("str", tout << "WARNING: expression " << mk_ismt2_pp(n1, m) << " was not internalized" << std::endl;);
ctx.internalize(n1, false);
}
if (!ctx.e_internalized(n2)) {
TRACE("str", tout << "WARNING: expression " << mk_ismt2_pp(n2, m) << " was not internalized" << std::endl;);
ctx.internalize(n2, false);
}
expr * curr = get_eqc_next(n1);
while (curr != n1) {
if (curr == n2)
return true;
curr = get_eqc_next(curr);
}
return false;
}
expr * theory_str::collect_eq_nodes(expr * n, expr_ref_vector & eqcSet) {
expr * constStrNode = NULL;
expr * ex = n;
do {
if (u.str.is_string(to_app(ex))) {
constStrNode = ex;
}
eqcSet.push_back(ex);
ex = get_eqc_next(ex);
} while (ex != n);
return constStrNode;
}
/*
* Collect constant strings (from left to right) in an AST node.
*/
void theory_str::get_const_str_asts_in_node(expr * node, expr_ref_vector & astList) {
if (u.str.is_string(node)) {
astList.push_back(node);
//} else if (getNodeType(t, node) == my_Z3_Func) {
} else if (is_app(node)) {
app * func_app = to_app(node);
unsigned int argCount = func_app->get_num_args();
for (unsigned int i = 0; i < argCount; i++) {
expr * argAst = func_app->get_arg(i);
get_const_str_asts_in_node(argAst, astList);
}
}
}
void theory_str::check_contain_by_eqc_val(expr * varNode, expr * constNode) {
context & ctx = get_context();
ast_manager & m = get_manager();
TRACE("str", tout << "varNode = " << mk_pp(varNode, m) << ", constNode = " << mk_pp(constNode, m) << std::endl;);
expr_ref_vector litems(m);
if (contain_pair_idx_map.find(varNode) != contain_pair_idx_map.end()) {
std::set<std::pair<expr*, expr*> >::iterator itor1 = contain_pair_idx_map[varNode].begin();
for (; itor1 != contain_pair_idx_map[varNode].end(); ++itor1) {
expr * strAst = itor1->first;
expr * substrAst = itor1->second;
expr * boolVar;
if (!contain_pair_bool_map.find(strAst, substrAst, boolVar)) {
TRACE("str", tout << "warning: no entry for boolVar in contain_pair_bool_map" << std::endl;);
}
// we only want to inspect the Contains terms where either of strAst or substrAst
// are equal to varNode.
TRACE("t_str_detail", tout << "considering Contains with strAst = " << mk_pp(strAst, m) << ", substrAst = " << mk_pp(substrAst, m) << "..." << std::endl;);
if (varNode != strAst && varNode != substrAst) {
TRACE("str", tout << "varNode not equal to strAst or substrAst, skip" << std::endl;);
continue;
}
TRACE("str", tout << "varNode matched one of strAst or substrAst. Continuing" << std::endl;);
// varEqcNode is str
if (strAst == varNode) {
expr_ref implyR(m);
litems.reset();
if (strAst != constNode) {
litems.push_back(ctx.mk_eq_atom(strAst, constNode));
}
zstring strConst;
u.str.is_string(constNode, strConst);
bool subStrHasEqcValue = false;
expr * substrValue = get_eqc_value(substrAst, subStrHasEqcValue);
if (substrValue != substrAst) {
litems.push_back(ctx.mk_eq_atom(substrAst, substrValue));
}
if (subStrHasEqcValue) {
// subStr has an eqc constant value
zstring subStrConst;
u.str.is_string(substrValue, subStrConst);
TRACE("t_str_detail", tout << "strConst = " << strConst << ", subStrConst = " << subStrConst << "\n";);
if (strConst.contains(subStrConst)) {
//implyR = ctx.mk_eq(ctx, boolVar, Z3_mk_true(ctx));
implyR = boolVar;
} else {
//implyR = Z3_mk_eq(ctx, boolVar, Z3_mk_false(ctx));
implyR = m.mk_not(boolVar);
}
} else {
// ------------------------------------------------------------------------------------------------
// subStr doesn't have an eqc contant value
// however, subStr equals to some concat(arg_1, arg_2, ..., arg_n)
// if arg_j is a constant and is not a part of the strConst, it's sure that the contains is false
// ** This check is needed here because the "strConst" and "strAst" may not be in a same eqc yet
// ------------------------------------------------------------------------------------------------
// collect eqc concat
std::set<expr*> eqcConcats;
get_concats_in_eqc(substrAst, eqcConcats);
for (std::set<expr*>::iterator concatItor = eqcConcats.begin();
concatItor != eqcConcats.end(); concatItor++) {
expr_ref_vector constList(m);
bool counterEgFound = false;
// get constant strings in concat
expr * aConcat = *concatItor;
get_const_str_asts_in_node(aConcat, constList);
for (expr_ref_vector::iterator cstItor = constList.begin();
cstItor != constList.end(); cstItor++) {
zstring pieceStr;
u.str.is_string(*cstItor, pieceStr);
if (!strConst.contains(pieceStr)) {
counterEgFound = true;
if (aConcat != substrAst) {
litems.push_back(ctx.mk_eq_atom(substrAst, aConcat));
}
//implyR = Z3_mk_eq(ctx, boolVar, Z3_mk_false(ctx));
implyR = m.mk_not(boolVar);
break;
}
}
if (counterEgFound) {
TRACE("str", tout << "Inconsistency found!" << std::endl;);
break;
}
}
}
// add assertion
if (implyR) {
expr_ref implyLHS(mk_and(litems), m);
assert_implication(implyLHS, implyR);
}
}
// varEqcNode is subStr
else if (substrAst == varNode) {
expr_ref implyR(m);
litems.reset();
if (substrAst != constNode) {
litems.push_back(ctx.mk_eq_atom(substrAst, constNode));
}
bool strHasEqcValue = false;
expr * strValue = get_eqc_value(strAst, strHasEqcValue);
if (strValue != strAst) {
litems.push_back(ctx.mk_eq_atom(strAst, strValue));
}
if (strHasEqcValue) {
zstring strConst, subStrConst;
u.str.is_string(strValue, strConst);
u.str.is_string(constNode, subStrConst);
if (strConst.contains(subStrConst)) {
//implyR = Z3_mk_eq(ctx, boolVar, Z3_mk_true(ctx));
implyR = boolVar;
} else {
// implyR = Z3_mk_eq(ctx, boolVar, Z3_mk_false(ctx));
implyR = m.mk_not(boolVar);
}
}
// add assertion
if (implyR) {
expr_ref implyLHS(mk_and(litems), m);
assert_implication(implyLHS, implyR);
}
}
} // for (itor1 : contains_map)
} // if varNode in contain_pair_idx_map
}
void theory_str::check_contain_by_substr(expr * varNode, expr_ref_vector & willEqClass) {
context & ctx = get_context();
ast_manager & m = get_manager();
expr_ref_vector litems(m);
if (contain_pair_idx_map.find(varNode) != contain_pair_idx_map.end()) {
std::set<std::pair<expr*, expr*> >::iterator itor1 = contain_pair_idx_map[varNode].begin();
for (; itor1 != contain_pair_idx_map[varNode].end(); ++itor1) {
expr * strAst = itor1->first;
expr * substrAst = itor1->second;
expr * boolVar;
if (!contain_pair_bool_map.find(strAst, substrAst, boolVar)) {
TRACE("str", tout << "warning: no entry for boolVar in contain_pair_bool_map" << std::endl;);
}
// we only want to inspect the Contains terms where either of strAst or substrAst
// are equal to varNode.
TRACE("t_str_detail", tout << "considering Contains with strAst = " << mk_pp(strAst, m) << ", substrAst = " << mk_pp(substrAst, m) << "..." << std::endl;);
if (varNode != strAst && varNode != substrAst) {
TRACE("str", tout << "varNode not equal to strAst or substrAst, skip" << std::endl;);
continue;
}
TRACE("str", tout << "varNode matched one of strAst or substrAst. Continuing" << std::endl;);
if (substrAst == varNode) {
bool strAstHasVal = false;
expr * strValue = get_eqc_value(strAst, strAstHasVal);
if (strAstHasVal) {
TRACE("str", tout << mk_pp(strAst, m) << " has constant eqc value " << mk_pp(strValue, m) << std::endl;);
if (strValue != strAst) {
litems.push_back(ctx.mk_eq_atom(strAst, strValue));
}
zstring strConst;
u.str.is_string(strValue, strConst);
// iterate eqc (also eqc-to-be) of substr
for (expr_ref_vector::iterator itAst = willEqClass.begin(); itAst != willEqClass.end(); itAst++) {
bool counterEgFound = false;
if (u.str.is_concat(to_app(*itAst))) {
expr_ref_vector constList(m);
// get constant strings in concat
app * aConcat = to_app(*itAst);
get_const_str_asts_in_node(aConcat, constList);
for (expr_ref_vector::iterator cstItor = constList.begin();
cstItor != constList.end(); cstItor++) {
zstring pieceStr;
u.str.is_string(*cstItor, pieceStr);
if (!strConst.contains(pieceStr)) {
TRACE("str", tout << "Inconsistency found!" << std::endl;);
counterEgFound = true;
if (aConcat != substrAst) {
litems.push_back(ctx.mk_eq_atom(substrAst, aConcat));
}
expr_ref implyLHS(mk_and(litems), m);
expr_ref implyR(m.mk_not(boolVar), m);
assert_implication(implyLHS, implyR);
break;
}
}
}
if (counterEgFound) {
break;
}
}
}
}
}
} // varNode in contain_pair_idx_map
}
bool theory_str::in_contain_idx_map(expr * n) {
return contain_pair_idx_map.find(n) != contain_pair_idx_map.end();
}
void theory_str::check_contain_by_eq_nodes(expr * n1, expr * n2) {
context & ctx = get_context();
ast_manager & m = get_manager();
if (in_contain_idx_map(n1) && in_contain_idx_map(n2)) {
std::set<std::pair<expr*, expr*> >::iterator keysItor1 = contain_pair_idx_map[n1].begin();
std::set<std::pair<expr*, expr*> >::iterator keysItor2;
for (; keysItor1 != contain_pair_idx_map[n1].end(); keysItor1++) {
// keysItor1 is on set {<.., n1>, ..., <n1, ...>, ...}
std::pair<expr*, expr*> key1 = *keysItor1;
if (key1.first == n1 && key1.second == n2) {
expr_ref implyL(m);
expr_ref implyR(contain_pair_bool_map[key1], m);
if (n1 != n2) {
implyL = ctx.mk_eq_atom(n1, n2);
assert_implication(implyL, implyR);
} else {
assert_axiom(implyR);
}
}
for (keysItor2 = contain_pair_idx_map[n2].begin();
keysItor2 != contain_pair_idx_map[n2].end(); keysItor2++) {
// keysItor2 is on set {<.., n2>, ..., <n2, ...>, ...}
std::pair<expr*, expr*> key2 = *keysItor2;
// skip if the pair is eq
if (key1 == key2) {
continue;
}
// ***************************
// Case 1: Contains(m, ...) /\ Contains(n, ) /\ m = n
// ***************************
if (key1.first == n1 && key2.first == n2) {
expr * subAst1 = key1.second;
expr * subAst2 = key2.second;
bool subAst1HasValue = false;
bool subAst2HasValue = false;
expr * subValue1 = get_eqc_value(subAst1, subAst1HasValue);
expr * subValue2 = get_eqc_value(subAst2, subAst2HasValue);
TRACE("str",
tout << "(Contains " << mk_pp(n1, m) << " " << mk_pp(subAst1, m) << ")" << std::endl;
tout << "(Contains " << mk_pp(n2, m) << " " << mk_pp(subAst2, m) << ")" << std::endl;
if (subAst1 != subValue1) {
tout << mk_pp(subAst1, m) << " = " << mk_pp(subValue1, m) << std::endl;
}
if (subAst2 != subValue2) {
tout << mk_pp(subAst2, m) << " = " << mk_pp(subValue2, m) << std::endl;
}
);
if (subAst1HasValue && subAst2HasValue) {
expr_ref_vector litems1(m);
if (n1 != n2) {
litems1.push_back(ctx.mk_eq_atom(n1, n2));
}
if (subValue1 != subAst1) {
litems1.push_back(ctx.mk_eq_atom(subAst1, subValue1));
}
if (subValue2 != subAst2) {
litems1.push_back(ctx.mk_eq_atom(subAst2, subValue2));
}
zstring subConst1, subConst2;
u.str.is_string(subValue1, subConst1);
u.str.is_string(subValue2, subConst2);
expr_ref implyR(m);
if (subConst1 == subConst2) {
// key1.first = key2.first /\ key1.second = key2.second
// ==> (containPairBoolMap[key1] = containPairBoolMap[key2])
implyR = ctx.mk_eq_atom(contain_pair_bool_map[key1], contain_pair_bool_map[key2]);
} else if (subConst1.contains(subConst2)) {
// key1.first = key2.first /\ Contains(key1.second, key2.second)
// ==> (containPairBoolMap[key1] --> containPairBoolMap[key2])
implyR = rewrite_implication(contain_pair_bool_map[key1], contain_pair_bool_map[key2]);
} else if (subConst2.contains(subConst1)) {
// key1.first = key2.first /\ Contains(key2.second, key1.second)
// ==> (containPairBoolMap[key2] --> containPairBoolMap[key1])
implyR = rewrite_implication(contain_pair_bool_map[key2], contain_pair_bool_map[key1]);
}
if (implyR) {
if (litems1.empty()) {
assert_axiom(implyR);
} else {
assert_implication(mk_and(litems1), implyR);
}
}
} else {
expr_ref_vector subAst1Eqc(m);
expr_ref_vector subAst2Eqc(m);
collect_eq_nodes(subAst1, subAst1Eqc);
collect_eq_nodes(subAst2, subAst2Eqc);
if (subAst1Eqc.contains(subAst2)) {
// -----------------------------------------------------------
// * key1.first = key2.first /\ key1.second = key2.second
// --> containPairBoolMap[key1] = containPairBoolMap[key2]
// -----------------------------------------------------------
expr_ref_vector litems2(m);
if (n1 != n2) {
litems2.push_back(ctx.mk_eq_atom(n1, n2));
}
if (subAst1 != subAst2) {
litems2.push_back(ctx.mk_eq_atom(subAst1, subAst2));
}
expr_ref implyR(ctx.mk_eq_atom(contain_pair_bool_map[key1], contain_pair_bool_map[key2]), m);
if (litems2.empty()) {
assert_axiom(implyR);
} else {
assert_implication(mk_and(litems2), implyR);
}
} else {
// -----------------------------------------------------------
// * key1.first = key2.first
// check eqc(key1.second) and eqc(key2.second)
// -----------------------------------------------------------
expr_ref_vector::iterator eqItorSub1 = subAst1Eqc.begin();
for (; eqItorSub1 != subAst1Eqc.end(); eqItorSub1++) {
expr_ref_vector::iterator eqItorSub2 = subAst2Eqc.begin();
for (; eqItorSub2 != subAst2Eqc.end(); eqItorSub2++) {
// ------------
// key1.first = key2.first /\ containPairBoolMap[<eqc(key1.second), eqc(key2.second)>]
// ==> (containPairBoolMap[key1] --> containPairBoolMap[key2])
// ------------
{
expr_ref_vector litems3(m);
if (n1 != n2) {
litems3.push_back(ctx.mk_eq_atom(n1, n2));
}
expr * eqSubVar1 = *eqItorSub1;
if (eqSubVar1 != subAst1) {
litems3.push_back(ctx.mk_eq_atom(subAst1, eqSubVar1));
}
expr * eqSubVar2 = *eqItorSub2;
if (eqSubVar2 != subAst2) {
litems3.push_back(ctx.mk_eq_atom(subAst2, eqSubVar2));
}
std::pair<expr*, expr*> tryKey1 = std::make_pair(eqSubVar1, eqSubVar2);
if (contain_pair_bool_map.contains(tryKey1)) {
TRACE("str", tout << "(Contains " << mk_pp(eqSubVar1, m) << " " << mk_pp(eqSubVar2, m) << ")" << std::endl;);
litems3.push_back(contain_pair_bool_map[tryKey1]);
expr_ref implR(rewrite_implication(contain_pair_bool_map[key1], contain_pair_bool_map[key2]), m);
assert_implication(mk_and(litems3), implR);
}
}
// ------------
// key1.first = key2.first /\ containPairBoolMap[<eqc(key2.second), eqc(key1.second)>]
// ==> (containPairBoolMap[key2] --> containPairBoolMap[key1])
// ------------
{
expr_ref_vector litems4(m);
if (n1 != n2) {
litems4.push_back(ctx.mk_eq_atom(n1, n2));
}
expr * eqSubVar1 = *eqItorSub1;
if (eqSubVar1 != subAst1) {
litems4.push_back(ctx.mk_eq_atom(subAst1, eqSubVar1));
}
expr * eqSubVar2 = *eqItorSub2;
if (eqSubVar2 != subAst2) {
litems4.push_back(ctx.mk_eq_atom(subAst2, eqSubVar2));
}
std::pair<expr*, expr*> tryKey2 = std::make_pair(eqSubVar2, eqSubVar1);
if (contain_pair_bool_map.contains(tryKey2)) {
TRACE("str", tout << "(Contains " << mk_pp(eqSubVar2, m) << " " << mk_pp(eqSubVar1, m) << ")" << std::endl;);
litems4.push_back(contain_pair_bool_map[tryKey2]);
expr_ref implR(rewrite_implication(contain_pair_bool_map[key2], contain_pair_bool_map[key1]), m);
assert_implication(mk_and(litems4), implR);
}
}
}
}
}
}
}
// ***************************
// Case 2: Contains(..., m) /\ Contains(... , n) /\ m = n
// ***************************
else if (key1.second == n1 && key2.second == n2) {
expr * str1 = key1.first;
expr * str2 = key2.first;
bool str1HasValue = false;
bool str2HasValue = false;
expr * strVal1 = get_eqc_value(str1, str1HasValue);
expr * strVal2 = get_eqc_value(str2, str2HasValue);
TRACE("str",
tout << "(Contains " << mk_pp(str1, m) << " " << mk_pp(n1, m) << ")" << std::endl;
tout << "(Contains " << mk_pp(str2, m) << " " << mk_pp(n2, m) << ")" << std::endl;
if (str1 != strVal1) {
tout << mk_pp(str1, m) << " = " << mk_pp(strVal1, m) << std::endl;
}
if (str2 != strVal2) {
tout << mk_pp(str2, m) << " = " << mk_pp(strVal2, m) << std::endl;
}
);
if (str1HasValue && str2HasValue) {
expr_ref_vector litems1(m);
if (n1 != n2) {
litems1.push_back(ctx.mk_eq_atom(n1, n2));
}
if (strVal1 != str1) {
litems1.push_back(ctx.mk_eq_atom(str1, strVal1));
}
if (strVal2 != str2) {
litems1.push_back(ctx.mk_eq_atom(str2, strVal2));
}
zstring const1, const2;
u.str.is_string(strVal1, const1);
u.str.is_string(strVal2, const2);
expr_ref implyR(m);
if (const1 == const2) {
// key1.second = key2.second /\ key1.first = key2.first
// ==> (containPairBoolMap[key1] = containPairBoolMap[key2])
implyR = ctx.mk_eq_atom(contain_pair_bool_map[key1], contain_pair_bool_map[key2]);
} else if (const1.contains(const2)) {
// key1.second = key2.second /\ Contains(key1.first, key2.first)
// ==> (containPairBoolMap[key2] --> containPairBoolMap[key1])
implyR = rewrite_implication(contain_pair_bool_map[key2], contain_pair_bool_map[key1]);
} else if (const2.contains(const1)) {
// key1.first = key2.first /\ Contains(key2.first, key1.first)
// ==> (containPairBoolMap[key1] --> containPairBoolMap[key2])
implyR = rewrite_implication(contain_pair_bool_map[key1], contain_pair_bool_map[key2]);
}
if (implyR) {
if (litems1.size() == 0) {
assert_axiom(implyR);
} else {
assert_implication(mk_and(litems1), implyR);
}
}
}
else {
expr_ref_vector str1Eqc(m);
expr_ref_vector str2Eqc(m);
collect_eq_nodes(str1, str1Eqc);
collect_eq_nodes(str2, str2Eqc);
if (str1Eqc.contains(str2)) {
// -----------------------------------------------------------
// * key1.first = key2.first /\ key1.second = key2.second
// --> containPairBoolMap[key1] = containPairBoolMap[key2]
// -----------------------------------------------------------
expr_ref_vector litems2(m);
if (n1 != n2) {
litems2.push_back(ctx.mk_eq_atom(n1, n2));
}
if (str1 != str2) {
litems2.push_back(ctx.mk_eq_atom(str1, str2));
}
expr_ref implyR(ctx.mk_eq_atom(contain_pair_bool_map[key1], contain_pair_bool_map[key2]), m);
if (litems2.empty()) {
assert_axiom(implyR);
} else {
assert_implication(mk_and(litems2), implyR);
}
} else {
// -----------------------------------------------------------
// * key1.second = key2.second
// check eqc(key1.first) and eqc(key2.first)
// -----------------------------------------------------------
expr_ref_vector::iterator eqItorStr1 = str1Eqc.begin();
for (; eqItorStr1 != str1Eqc.end(); eqItorStr1++) {
expr_ref_vector::iterator eqItorStr2 = str2Eqc.begin();
for (; eqItorStr2 != str2Eqc.end(); eqItorStr2++) {
{
expr_ref_vector litems3(m);
if (n1 != n2) {
litems3.push_back(ctx.mk_eq_atom(n1, n2));
}
expr * eqStrVar1 = *eqItorStr1;
if (eqStrVar1 != str1) {
litems3.push_back(ctx.mk_eq_atom(str1, eqStrVar1));
}
expr * eqStrVar2 = *eqItorStr2;
if (eqStrVar2 != str2) {
litems3.push_back(ctx.mk_eq_atom(str2, eqStrVar2));
}
std::pair<expr*, expr*> tryKey1 = std::make_pair(eqStrVar1, eqStrVar2);
if (contain_pair_bool_map.contains(tryKey1)) {
TRACE("str", tout << "(Contains " << mk_pp(eqStrVar1, m) << " " << mk_pp(eqStrVar2, m) << ")" << std::endl;);
litems3.push_back(contain_pair_bool_map[tryKey1]);
// ------------
// key1.second = key2.second /\ containPairBoolMap[<eqc(key1.first), eqc(key2.first)>]
// ==> (containPairBoolMap[key2] --> containPairBoolMap[key1])
// ------------
expr_ref implR(rewrite_implication(contain_pair_bool_map[key2], contain_pair_bool_map[key1]), m);
assert_implication(mk_and(litems3), implR);
}
}
{
expr_ref_vector litems4(m);
if (n1 != n2) {
litems4.push_back(ctx.mk_eq_atom(n1, n2));
}
expr * eqStrVar1 = *eqItorStr1;
if (eqStrVar1 != str1) {
litems4.push_back(ctx.mk_eq_atom(str1, eqStrVar1));
}
expr *eqStrVar2 = *eqItorStr2;
if (eqStrVar2 != str2) {
litems4.push_back(ctx.mk_eq_atom(str2, eqStrVar2));
}
std::pair<expr*, expr*> tryKey2 = std::make_pair(eqStrVar2, eqStrVar1);
if (contain_pair_bool_map.contains(tryKey2)) {
TRACE("str", tout << "(Contains " << mk_pp(eqStrVar2, m) << " " << mk_pp(eqStrVar1, m) << ")" << std::endl;);
litems4.push_back(contain_pair_bool_map[tryKey2]);
// ------------
// key1.first = key2.first /\ containPairBoolMap[<eqc(key2.second), eqc(key1.second)>]
// ==> (containPairBoolMap[key1] --> containPairBoolMap[key2])
// ------------
expr_ref implR(rewrite_implication(contain_pair_bool_map[key1], contain_pair_bool_map[key2]), m);
assert_implication(mk_and(litems4), implR);
}
}
}
}
}
}
}
}
if (n1 == n2) {
break;
}
}
} // (in_contain_idx_map(n1) && in_contain_idx_map(n2))
}
void theory_str::check_contain_in_new_eq(expr * n1, expr * n2) {
if (contains_map.empty()) {
return;
}
ast_manager & m = get_manager();
TRACE("str", tout << "consistency check for contains wrt. " << mk_pp(n1, m) << " and " << mk_pp(n2, m) << std::endl;);
expr_ref_vector willEqClass(m);
expr * constStrAst_1 = collect_eq_nodes(n1, willEqClass);
expr * constStrAst_2 = collect_eq_nodes(n2, willEqClass);
expr * constStrAst = (constStrAst_1 != NULL) ? constStrAst_1 : constStrAst_2;
TRACE("str", tout << "eqc of n1 is {";
for (expr_ref_vector::iterator it = willEqClass.begin(); it != willEqClass.end(); ++it) {
expr * el = *it;
tout << " " << mk_pp(el, m);
}
tout << std::endl;
if (constStrAst == NULL) {
tout << "constStrAst = NULL" << std::endl;
} else {
tout << "constStrAst = " << mk_pp(constStrAst, m) << std::endl;
}
);
// step 1: we may have constant values for Contains checks now
if (constStrAst != NULL) {
expr_ref_vector::iterator itAst = willEqClass.begin();
for (; itAst != willEqClass.end(); itAst++) {
if (*itAst == constStrAst) {
continue;
}
check_contain_by_eqc_val(*itAst, constStrAst);
}
} else {
// no concrete value to be put in eqc, solely based on context
// Check here is used to detected the facts as follows:
// * known: contains(Z, Y) /\ Z = "abcdefg" /\ Y = M
// * new fact: M = concat(..., "jio", ...)
// Note that in this branch, either M or concat(..., "jio", ...) has a constant value
// So, only need to check
// * "EQC(M) U EQC(concat(..., "jio", ...))" as substr and
// * If strAst registered has an eqc constant in the context
// -------------------------------------------------------------
expr_ref_vector::iterator itAst = willEqClass.begin();
for (; itAst != willEqClass.end(); ++itAst) {
check_contain_by_substr(*itAst, willEqClass);
}
}
// ------------------------------------------
// step 2: check for b1 = contains(x, m), b2 = contains(y, n)
// (1) x = y /\ m = n ==> b1 = b2
// (2) x = y /\ Contains(const(m), const(n)) ==> (b1 -> b2)
// (3) x = y /\ Contains(const(n), const(m)) ==> (b2 -> b1)
// (4) x = y /\ containPairBoolMap[<eqc(m), eqc(n)>] ==> (b1 -> b2)
// (5) x = y /\ containPairBoolMap[<eqc(n), eqc(m)>] ==> (b2 -> b1)
// (6) Contains(const(x), const(y)) /\ m = n ==> (b2 -> b1)
// (7) Contains(const(y), const(x)) /\ m = n ==> (b1 -> b2)
// (8) containPairBoolMap[<eqc(x), eqc(y)>] /\ m = n ==> (b2 -> b1)
// (9) containPairBoolMap[<eqc(y), eqc(x)>] /\ m = n ==> (b1 -> b2)
// ------------------------------------------
expr_ref_vector::iterator varItor1 = willEqClass.begin();
for (; varItor1 != willEqClass.end(); ++varItor1) {
expr * varAst1 = *varItor1;
expr_ref_vector::iterator varItor2 = varItor1;
for (; varItor2 != willEqClass.end(); ++varItor2) {
expr * varAst2 = *varItor2;
check_contain_by_eq_nodes(varAst1, varAst2);
}
}
}
expr * theory_str::dealias_node(expr * node, std::map<expr*, expr*> & varAliasMap, std::map<expr*, expr*> & concatAliasMap) {
if (variable_set.find(node) != variable_set.end()) {
return get_alias_index_ast(varAliasMap, node);
} else if (u.str.is_concat(to_app(node))) {
return get_alias_index_ast(concatAliasMap, node);
}
return node;
}
void theory_str::get_grounded_concats(expr* node, std::map<expr*, expr*> & varAliasMap,
std::map<expr*, expr*> & concatAliasMap, std::map<expr*, expr*> & varConstMap,
std::map<expr*, expr*> & concatConstMap, std::map<expr*, std::map<expr*, int> > & varEqConcatMap,
std::map<expr*, std::map<std::vector<expr*>, std::set<expr*> > > & groundedMap) {
if (u.re.is_unroll(to_app(node))) {
return;
}
// **************************************************
// first deAlias the node if it is a var or concat
// **************************************************
node = dealias_node(node, varAliasMap, concatAliasMap);
if (groundedMap.find(node) != groundedMap.end()) {
return;
}
// haven't computed grounded concats for "node" (de-aliased)
// ---------------------------------------------------------
context & ctx = get_context();
// const strings: node is de-aliased
if (u.str.is_string(node)) {
std::vector<expr*> concatNodes;
concatNodes.push_back(node);
groundedMap[node][concatNodes].clear(); // no condition
}
// Concat functions
else if (u.str.is_concat(to_app(node))) {
// if "node" equals to a constant string, thenjust push the constant into the concat vector
// Again "node" has been de-aliased at the very beginning
if (concatConstMap.find(node) != concatConstMap.end()) {
std::vector<expr*> concatNodes;
concatNodes.push_back(concatConstMap[node]);
groundedMap[node][concatNodes].clear();
groundedMap[node][concatNodes].insert(ctx.mk_eq_atom(node, concatConstMap[node]));
}
// node doesn't have eq constant value. Process its children.
else {
// merge arg0 and arg1
expr * arg0 = to_app(node)->get_arg(0);
expr * arg1 = to_app(node)->get_arg(1);
expr * arg0DeAlias = dealias_node(arg0, varAliasMap, concatAliasMap);
expr * arg1DeAlias = dealias_node(arg1, varAliasMap, concatAliasMap);
get_grounded_concats(arg0DeAlias, varAliasMap, concatAliasMap, varConstMap, concatConstMap, varEqConcatMap, groundedMap);
get_grounded_concats(arg1DeAlias, varAliasMap, concatAliasMap, varConstMap, concatConstMap, varEqConcatMap, groundedMap);
std::map<std::vector<expr*>, std::set<expr*> >::iterator arg0_grdItor = groundedMap[arg0DeAlias].begin();
std::map<std::vector<expr*>, std::set<expr*> >::iterator arg1_grdItor;
for (; arg0_grdItor != groundedMap[arg0DeAlias].end(); arg0_grdItor++) {
arg1_grdItor = groundedMap[arg1DeAlias].begin();
for (; arg1_grdItor != groundedMap[arg1DeAlias].end(); arg1_grdItor++) {
std::vector<expr*> ndVec;
ndVec.insert(ndVec.end(), arg0_grdItor->first.begin(), arg0_grdItor->first.end());
int arg0VecSize = arg0_grdItor->first.size();
int arg1VecSize = arg1_grdItor->first.size();
if (arg0VecSize > 0 && arg1VecSize > 0 && u.str.is_string(arg0_grdItor->first[arg0VecSize - 1]) && u.str.is_string(arg1_grdItor->first[0])) {
ndVec.pop_back();
ndVec.push_back(mk_concat(arg0_grdItor->first[arg0VecSize - 1], arg1_grdItor->first[0]));
for (int i = 1; i < arg1VecSize; i++) {
ndVec.push_back(arg1_grdItor->first[i]);
}
} else {
ndVec.insert(ndVec.end(), arg1_grdItor->first.begin(), arg1_grdItor->first.end());
}
// only insert if we don't know "node = concat(ndVec)" since one set of condition leads to this is enough
if (groundedMap[node].find(ndVec) == groundedMap[node].end()) {
groundedMap[node][ndVec];
if (arg0 != arg0DeAlias) {
groundedMap[node][ndVec].insert(ctx.mk_eq_atom(arg0, arg0DeAlias));
}
groundedMap[node][ndVec].insert(arg0_grdItor->second.begin(), arg0_grdItor->second.end());
if (arg1 != arg1DeAlias) {
groundedMap[node][ndVec].insert(ctx.mk_eq_atom(arg1, arg1DeAlias));
}
groundedMap[node][ndVec].insert(arg1_grdItor->second.begin(), arg1_grdItor->second.end());
}
}
}
}
}
// string variables
else if (variable_set.find(node) != variable_set.end()) {
// deAliasedVar = Constant
if (varConstMap.find(node) != varConstMap.end()) {
std::vector<expr*> concatNodes;
concatNodes.push_back(varConstMap[node]);
groundedMap[node][concatNodes].clear();
groundedMap[node][concatNodes].insert(ctx.mk_eq_atom(node, varConstMap[node]));
}
// deAliasedVar = someConcat
else if (varEqConcatMap.find(node) != varEqConcatMap.end()) {
expr * eqConcat = varEqConcatMap[node].begin()->first;
expr * deAliasedEqConcat = dealias_node(eqConcat, varAliasMap, concatAliasMap);
get_grounded_concats(deAliasedEqConcat, varAliasMap, concatAliasMap, varConstMap, concatConstMap, varEqConcatMap, groundedMap);
std::map<std::vector<expr*>, std::set<expr*> >::iterator grdItor = groundedMap[deAliasedEqConcat].begin();
for (; grdItor != groundedMap[deAliasedEqConcat].end(); grdItor++) {
std::vector<expr*> ndVec;
ndVec.insert(ndVec.end(), grdItor->first.begin(), grdItor->first.end());
// only insert if we don't know "node = concat(ndVec)" since one set of condition leads to this is enough
if (groundedMap[node].find(ndVec) == groundedMap[node].end()) {
// condition: node = deAliasedEqConcat
groundedMap[node][ndVec].insert(ctx.mk_eq_atom(node, deAliasedEqConcat));
// appending conditions for "deAliasedEqConcat = CONCAT(ndVec)"
groundedMap[node][ndVec].insert(grdItor->second.begin(), grdItor->second.end());
}
}
}
// node (has been de-aliased) != constant && node (has been de-aliased) != any concat
// just push in the deAliasedVar
else {
std::vector<expr*> concatNodes;
concatNodes.push_back(node);
groundedMap[node][concatNodes];
}
}
}
void theory_str::print_grounded_concat(expr * node, std::map<expr*, std::map<std::vector<expr*>, std::set<expr*> > > & groundedMap) {
ast_manager & m = get_manager();
TRACE("str", tout << mk_pp(node, m) << std::endl;);
if (groundedMap.find(node) != groundedMap.end()) {
std::map<std::vector<expr*>, std::set<expr*> >::iterator itor = groundedMap[node].begin();
for (; itor != groundedMap[node].end(); ++itor) {
TRACE("str",
tout << "\t[grounded] ";
std::vector<expr*>::const_iterator vIt = itor->first.begin();
for (; vIt != itor->first.end(); ++vIt) {
tout << mk_pp(*vIt, m) << ", ";
}
tout << std::endl;
tout << "\t[condition] ";
std::set<expr*>::iterator sIt = itor->second.begin();
for (; sIt != itor->second.end(); sIt++) {
tout << mk_pp(*sIt, m) << ", ";
}
tout << std::endl;
);
}
} else {
TRACE("str", tout << "not found" << std::endl;);
}
}
bool theory_str::is_partial_in_grounded_concat(const std::vector<expr*> & strVec, const std::vector<expr*> & subStrVec) {
int strCnt = strVec.size();
int subStrCnt = subStrVec.size();
if (strCnt == 0 || subStrCnt == 0) {
return false;
}
// The assumption is that all consecutive constant strings are merged into one node
if (strCnt < subStrCnt) {
return false;
}
if (subStrCnt == 1) {
zstring subStrVal;
if (u.str.is_string(subStrVec[0], subStrVal)) {
for (int i = 0; i < strCnt; i++) {
zstring strVal;
if (u.str.is_string(strVec[i], strVal)) {
if (strVal.contains(subStrVal)) {
return true;
}
}
}
} else {
for (int i = 0; i < strCnt; i++) {
if (strVec[i] == subStrVec[0]) {
return true;
}
}
}
return false;
} else {
for (int i = 0; i <= (strCnt - subStrCnt); i++) {
// The first node in subStrVect should be
// * constant: a suffix of a note in strVec[i]
// * variable:
bool firstNodesOK = true;
zstring subStrHeadVal;
if (u.str.is_string(subStrVec[0], subStrHeadVal)) {
zstring strHeadVal;
if (u.str.is_string(strVec[i], strHeadVal)) {
if (strHeadVal.length() >= subStrHeadVal.length()) {
zstring suffix = strHeadVal.extract(strHeadVal.length() - subStrHeadVal.length(), subStrHeadVal.length());
if (suffix != subStrHeadVal) {
firstNodesOK = false;
}
} else {
firstNodesOK = false;
}
} else {
if (subStrVec[0] != strVec[i]) {
firstNodesOK = false;
}
}
}
if (!firstNodesOK) {
continue;
}
// middle nodes
bool midNodesOK = true;
for (int j = 1; j < subStrCnt - 1; j++) {
if (subStrVec[j] != strVec[i + j]) {
midNodesOK = false;
break;
}
}
if (!midNodesOK) {
continue;
}
// tail nodes
int tailIdx = i + subStrCnt - 1;
zstring subStrTailVal;
if (u.str.is_string(subStrVec[subStrCnt - 1], subStrTailVal)) {
zstring strTailVal;
if (u.str.is_string(strVec[tailIdx], strTailVal)) {
if (strTailVal.length() >= subStrTailVal.length()) {
zstring prefix = strTailVal.extract(0, subStrTailVal.length());
if (prefix == subStrTailVal) {
return true;
} else {
continue;
}
} else {
continue;
}
}
} else {
if (subStrVec[subStrCnt - 1] == strVec[tailIdx]) {
return true;
} else {
continue;
}
}
}
return false;
}
}
void theory_str::check_subsequence(expr* str, expr* strDeAlias, expr* subStr, expr* subStrDeAlias, expr* boolVar,
std::map<expr*, std::map<std::vector<expr*>, std::set<expr*> > > & groundedMap) {
context & ctx = get_context();
ast_manager & m = get_manager();
std::map<std::vector<expr*>, std::set<expr*> >::iterator itorStr = groundedMap[strDeAlias].begin();
std::map<std::vector<expr*>, std::set<expr*> >::iterator itorSubStr;
for (; itorStr != groundedMap[strDeAlias].end(); itorStr++) {
itorSubStr = groundedMap[subStrDeAlias].begin();
for (; itorSubStr != groundedMap[subStrDeAlias].end(); itorSubStr++) {
bool contain = is_partial_in_grounded_concat(itorStr->first, itorSubStr->first);
if (contain) {
expr_ref_vector litems(m);
if (str != strDeAlias) {
litems.push_back(ctx.mk_eq_atom(str, strDeAlias));
}
if (subStr != subStrDeAlias) {
litems.push_back(ctx.mk_eq_atom(subStr, subStrDeAlias));
}
//litems.insert(itorStr->second.begin(), itorStr->second.end());
//litems.insert(itorSubStr->second.begin(), itorSubStr->second.end());
for (std::set<expr*>::const_iterator i1 = itorStr->second.begin();
i1 != itorStr->second.end(); ++i1) {
litems.push_back(*i1);
}
for (std::set<expr*>::const_iterator i1 = itorSubStr->second.begin();
i1 != itorSubStr->second.end(); ++i1) {
litems.push_back(*i1);
}
expr_ref implyR(boolVar, m);
if (litems.empty()) {
assert_axiom(implyR);
} else {
expr_ref implyL(mk_and(litems), m);
assert_implication(implyL, implyR);
}
}
}
}
}
void theory_str::compute_contains(std::map<expr*, expr*> & varAliasMap,
std::map<expr*, expr*> & concatAliasMap, std::map<expr*, expr*> & varConstMap,
std::map<expr*, expr*> & concatConstMap, std::map<expr*, std::map<expr*, int> > & varEqConcatMap) {
std::map<expr*, std::map<std::vector<expr*>, std::set<expr*> > > groundedMap;
theory_str_contain_pair_bool_map_t::iterator containItor = contain_pair_bool_map.begin();
for (; containItor != contain_pair_bool_map.end(); containItor++) {
expr* containBoolVar = containItor->get_value();
expr* str = containItor->get_key1();
expr* subStr = containItor->get_key2();
expr* strDeAlias = dealias_node(str, varAliasMap, concatAliasMap);
expr* subStrDeAlias = dealias_node(subStr, varAliasMap, concatAliasMap);
get_grounded_concats(strDeAlias, varAliasMap, concatAliasMap, varConstMap, concatConstMap, varEqConcatMap, groundedMap);
get_grounded_concats(subStrDeAlias, varAliasMap, concatAliasMap, varConstMap, concatConstMap, varEqConcatMap, groundedMap);
// debugging
print_grounded_concat(strDeAlias, groundedMap);
print_grounded_concat(subStrDeAlias, groundedMap);
check_subsequence(str, strDeAlias, subStr, subStrDeAlias, containBoolVar, groundedMap);
}
}
bool theory_str::can_concat_eq_str(expr * concat, zstring& str) {
unsigned int strLen = str.length();
if (u.str.is_concat(to_app(concat))) {
ptr_vector<expr> args;
get_nodes_in_concat(concat, args);
expr * ml_node = args[0];
expr * mr_node = args[args.size() - 1];
zstring ml_str;
if (u.str.is_string(ml_node, ml_str)) {
unsigned int ml_len = ml_str.length();
if (ml_len > strLen) {
return false;
}
unsigned int cLen = ml_len;
if (ml_str != str.extract(0, cLen)) {
return false;
}
}
zstring mr_str;
if (u.str.is_string(mr_node, mr_str)) {
unsigned int mr_len = mr_str.length();
if (mr_len > strLen) {
return false;
}
unsigned int cLen = mr_len;
if (mr_str != str.extract(strLen - cLen, cLen)) {
return false;
}
}
unsigned int sumLen = 0;
for (unsigned int i = 0 ; i < args.size() ; i++) {
expr * oneArg = args[i];
zstring arg_str;
if (u.str.is_string(oneArg, arg_str)) {
if (!str.contains(arg_str)) {
return false;
}
sumLen += arg_str.length();
}
}
if (sumLen > strLen) {
return false;
}
}
return true;
}
bool theory_str::can_concat_eq_concat(expr * concat1, expr * concat2) {
if (u.str.is_concat(to_app(concat1)) && u.str.is_concat(to_app(concat2))) {
{
// Suppose concat1 = (Concat X Y) and concat2 = (Concat M N).
expr * concat1_mostL = getMostLeftNodeInConcat(concat1);
expr * concat2_mostL = getMostLeftNodeInConcat(concat2);
// if both X and M are constant strings, check whether they have the same prefix
zstring concat1_mostL_str, concat2_mostL_str;
if (u.str.is_string(concat1_mostL, concat1_mostL_str) && u.str.is_string(concat2_mostL, concat2_mostL_str)) {
unsigned int cLen = std::min(concat1_mostL_str.length(), concat2_mostL_str.length());
if (concat1_mostL_str.extract(0, cLen) != concat2_mostL_str.extract(0, cLen)) {
return false;
}
}
}
{
// Similarly, if both Y and N are constant strings, check whether they have the same suffix
expr * concat1_mostR = getMostRightNodeInConcat(concat1);
expr * concat2_mostR = getMostRightNodeInConcat(concat2);
zstring concat1_mostR_str, concat2_mostR_str;
if (u.str.is_string(concat1_mostR, concat1_mostR_str) && u.str.is_string(concat2_mostR, concat2_mostR_str)) {
unsigned int cLen = std::min(concat1_mostR_str.length(), concat2_mostR_str.length());
if (concat1_mostR_str.extract(concat1_mostR_str.length() - cLen, cLen) !=
concat2_mostR_str.extract(concat2_mostR_str.length() - cLen, cLen)) {
return false;
}
}
}
}
return true;
}
/*
* Check whether n1 and n2 could be equal.
* Returns true if n1 could equal n2 (maybe),
* and false if n1 is definitely not equal to n2 (no).
*/
bool theory_str::can_two_nodes_eq(expr * n1, expr * n2) {
app * n1_curr = to_app(n1);
app * n2_curr = to_app(n2);
// case 0: n1_curr is const string, n2_curr is const string
if (u.str.is_string(n1_curr) && u.str.is_string(n2_curr)) {
if (n1_curr != n2_curr) {
return false;
}
}
// case 1: n1_curr is concat, n2_curr is const string
else if (u.str.is_concat(n1_curr) && u.str.is_string(n2_curr)) {
zstring n2_curr_str;
u.str.is_string(n2_curr, n2_curr_str);
if (!can_concat_eq_str(n1_curr, n2_curr_str)) {
return false;
}
}
// case 2: n2_curr is concat, n1_curr is const string
else if (u.str.is_concat(n2_curr) && u.str.is_string(n1_curr)) {
zstring n1_curr_str;
u.str.is_string(n1_curr, n1_curr_str);
if (!can_concat_eq_str(n2_curr, n1_curr_str)) {
return false;
}
}
// case 3: both are concats
else if (u.str.is_concat(n1_curr) && u.str.is_concat(n2_curr)) {
if (!can_concat_eq_concat(n1_curr, n2_curr)) {
return false;
}
}
return true;
}
// was checkLength2ConstStr() in Z3str2
// 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) {
ast_manager & mgr = get_manager();
context & ctx = get_context();
zstring tmp;
u.str.is_string(constStr, tmp);
rational strLen(tmp.length());
if (u.str.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 (!u.str.is_string(args[i])) {
items.push_back(ctx.mk_eq_atom(mk_strlen(args[i]), mk_int(argLen)));
}
TRACE("str", 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("str", 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("str", 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;
}
bool theory_str::check_length_concat_concat(expr * n1, expr * n2) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
ptr_vector<expr> concat1Args;
ptr_vector<expr> concat2Args;
get_nodes_in_concat(n1, concat1Args);
get_nodes_in_concat(n2, concat2Args);
bool concat1LenFixed = true;
bool concat2LenFixed = true;
expr_ref_vector items(mgr);
rational sum1(0), sum2(0);
for (unsigned int i = 0; i < concat1Args.size(); ++i) {
expr * oneArg = concat1Args[i];
rational argLen;
bool argLen_exists = get_len_value(oneArg, argLen);
if (argLen_exists) {
sum1 += argLen;
if (!u.str.is_string(oneArg)) {
items.push_back(ctx.mk_eq_atom(mk_strlen(oneArg), mk_int(argLen)));
}
} else {
concat1LenFixed = false;
}
}
for (unsigned int i = 0; i < concat2Args.size(); ++i) {
expr * oneArg = concat2Args[i];
rational argLen;
bool argLen_exists = get_len_value(oneArg, argLen);
if (argLen_exists) {
sum2 += argLen;
if (!u.str.is_string(oneArg)) {
items.push_back(ctx.mk_eq_atom(mk_strlen(oneArg), mk_int(argLen)));
}
} else {
concat2LenFixed = false;
}
}
items.push_back(ctx.mk_eq_atom(n1, n2));
bool conflict = false;
if (concat1LenFixed && concat2LenFixed) {
if (sum1 != sum2) {
conflict = true;
}
} else if (!concat1LenFixed && concat2LenFixed) {
if (sum1 > sum2) {
conflict = true;
}
} else if (concat1LenFixed && !concat2LenFixed) {
if (sum1 < sum2) {
conflict = true;
}
}
if (conflict) {
TRACE("str", tout << "inconsistent length detected in concat <==> concat" << std::endl;);
expr_ref toAssert(mgr.mk_not(mk_and(items)), mgr);
assert_axiom(toAssert);
return false;
}
return true;
}
bool theory_str::check_length_concat_var(expr * concat, expr * var) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
rational varLen;
bool varLen_exists = get_len_value(var, varLen);
if (!varLen_exists) {
return true;
} else {
rational sumLen(0);
ptr_vector<expr> args;
expr_ref_vector items(mgr);
get_nodes_in_concat(concat, args);
for (unsigned int i = 0; i < args.size(); ++i) {
expr * oneArg = args[i];
rational argLen;
bool argLen_exists = get_len_value(oneArg, argLen);
if (argLen_exists) {
if (!u.str.is_string(oneArg) && !argLen.is_zero()) {
items.push_back(ctx.mk_eq_atom(mk_strlen(oneArg), mk_int(argLen)));
}
sumLen += argLen;
if (sumLen > varLen) {
TRACE("str", tout << "inconsistent length detected in concat <==> var" << std::endl;);
items.push_back(ctx.mk_eq_atom(mk_strlen(var), mk_int(varLen)));
items.push_back(ctx.mk_eq_atom(concat, var));
expr_ref toAssert(mgr.mk_not(mk_and(items)), mgr);
assert_axiom(toAssert);
return false;
}
}
}
return true;
}
}
bool theory_str::check_length_var_var(expr * var1, expr * var2) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
rational var1Len, var2Len;
bool var1Len_exists = get_len_value(var1, var1Len);
bool var2Len_exists = get_len_value(var2, var2Len);
if (var1Len_exists && var2Len_exists && var1Len != var2Len) {
TRACE("str", tout << "inconsistent length detected in var <==> var" << std::endl;);
expr_ref_vector items(mgr);
items.push_back(ctx.mk_eq_atom(mk_strlen(var1), mk_int(var1Len)));
items.push_back(ctx.mk_eq_atom(mk_strlen(var2), mk_int(var2Len)));
items.push_back(ctx.mk_eq_atom(var1, var2));
expr_ref toAssert(mgr.mk_not(mk_and(items)), mgr);
assert_axiom(toAssert);
return false;
}
return true;
}
// 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_eq_var_concat(expr * n1, expr * n2) {
// n1 and n2 are not const string: either variable or concat
bool n1Concat = u.str.is_concat(to_app(n1));
bool n2Concat = u.str.is_concat(to_app(n2));
if (n1Concat && n2Concat) {
return check_length_concat_concat(n1, n2);
}
// n1 is concat, n2 is variable
else if (n1Concat && (!n2Concat)) {
return check_length_concat_var(n1, n2);
}
// n1 is variable, n2 is concat
else if ((!n1Concat) && n2Concat) {
return check_length_concat_var(n2, n1);
}
// n1 and n2 are both variables
else {
return check_length_var_var(n1, n2);
}
return true;
}
// returns false if an inconsistency is detected, or true if no inconsistencies were found
// - note that these are different from the semantics of checkLengConsistency() in Z3str2
bool theory_str::check_length_consistency(expr * n1, expr * n2) {
if (u.str.is_string(n1) && u.str.is_string(n2)) {
// consistency has already been checked in can_two_nodes_eq().
return true;
} else if (u.str.is_string(n1) && (!u.str.is_string(n2))) {
return check_length_const_string(n2, n1);
} else if (u.str.is_string(n2) && (!u.str.is_string(n1))) {
return check_length_const_string(n1, n2);
} else {
// n1 and n2 are vars or concats
return check_length_eq_var_concat(n1, n2);
}
return true;
}
// Modified signature: returns true if nothing was learned, or false if at least one axiom was asserted.
// (This is used for deferred consistency checking)
bool theory_str::check_concat_len_in_eqc(expr * concat) {
bool no_assertions = true;
expr * eqc_n = concat;
do {
if (u.str.is_concat(to_app(eqc_n))) {
rational unused;
bool status = infer_len_concat(eqc_n, unused);
if (status) {
no_assertions = false;
}
}
eqc_n = get_eqc_next(eqc_n);
} while (eqc_n != concat);
return no_assertions;
}
// Convert a regular expression to an e-NFA using Thompson's construction
void nfa::convert_re(expr * e, unsigned & start, unsigned & end, seq_util & u) {
start = next_id();
end = next_id();
if (u.re.is_to_re(e)) {
app * a = to_app(e);
expr * arg_str = a->get_arg(0);
zstring str;
if (u.str.is_string(arg_str, str)) {
TRACE("str", tout << "build NFA for '" << str << "'" << "\n";);
/*
* For an n-character string, we make (n-1) intermediate states,
* labelled i_(0) through i_(n-2).
* Then we construct the following transitions:
* start --str[0]--> i_(0) --str[1]--> i_(1) --...--> i_(n-2) --str[n-1]--> final
*/
unsigned last = start;
for (int i = 0; i <= ((int)str.length()) - 2; ++i) {
unsigned i_state = next_id();
make_transition(last, str[i], i_state);
TRACE("str", tout << "string transition " << last << "--" << str[i] << "--> " << i_state << "\n";);
last = i_state;
}
make_transition(last, str[(str.length() - 1)], end);
TRACE("str", tout << "string transition " << last << "--" << str[(str.length() - 1)] << "--> " << end << "\n";);
} else {
TRACE("str", tout << "invalid string constant in Str2Reg" << std::endl;);
m_valid = false;
return;
}
} else if (u.re.is_concat(e)){
app * a = to_app(e);
expr * re1 = a->get_arg(0);
expr * re2 = a->get_arg(1);
unsigned start1, end1;
convert_re(re1, start1, end1, u);
unsigned start2, end2;
convert_re(re2, start2, end2, u);
// start --e--> start1 --...--> end1 --e--> start2 --...--> end2 --e--> end
make_epsilon_move(start, start1);
make_epsilon_move(end1, start2);
make_epsilon_move(end2, end);
TRACE("str", tout << "concat NFA: start = " << start << ", end = " << end << std::endl;);
} else if (u.re.is_union(e)) {
app * a = to_app(e);
expr * re1 = a->get_arg(0);
expr * re2 = a->get_arg(1);
unsigned start1, end1;
convert_re(re1, start1, end1, u);
unsigned start2, end2;
convert_re(re2, start2, end2, u);
// start --e--> start1 ; start --e--> start2
// end1 --e--> end ; end2 --e--> end
make_epsilon_move(start, start1);
make_epsilon_move(start, start2);
make_epsilon_move(end1, end);
make_epsilon_move(end2, end);
TRACE("str", tout << "union NFA: start = " << start << ", end = " << end << std::endl;);
} else if (u.re.is_star(e)) {
app * a = to_app(e);
expr * subex = a->get_arg(0);
unsigned start_subex, end_subex;
convert_re(subex, start_subex, end_subex, u);
// start --e--> start_subex, start --e--> end
// end_subex --e--> start_subex, end_subex --e--> end
make_epsilon_move(start, start_subex);
make_epsilon_move(start, end);
make_epsilon_move(end_subex, start_subex);
make_epsilon_move(end_subex, end);
TRACE("str", tout << "star NFA: start = " << start << ", end = " << end << std::endl;);
} else if (u.re.is_range(e)) {
// range('a', 'z')
// start --'a'--> end
// start --'b'--> end
// ...
// start --'z'--> end
app * a = to_app(e);
expr * c1 = a->get_arg(0);
expr * c2 = a->get_arg(1);
zstring s_c1, s_c2;
u.str.is_string(c1, s_c1);
u.str.is_string(c2, s_c2);
unsigned int id1 = s_c1[0];
unsigned int id2 = s_c2[0];
if (id1 > id2) {
unsigned int tmp = id1;
id1 = id2;
id2 = tmp;
}
for (unsigned int i = id1; i <= id2; ++i) {
char ch = (char)i;
make_transition(start, ch, end);
}
TRACE("str", tout << "range NFA: start = " << start << ", end = " << end << std::endl;);
} else {
TRACE("str", tout << "invalid regular expression" << std::endl;);
m_valid = false;
return;
}
}
void nfa::epsilon_closure(unsigned start, std::set<unsigned> & closure) {
std::deque<unsigned> worklist;
closure.insert(start);
worklist.push_back(start);
while(!worklist.empty()) {
unsigned state = worklist.front();
worklist.pop_front();
if (epsilon_map.find(state) != epsilon_map.end()) {
for (std::set<unsigned>::iterator it = epsilon_map[state].begin();
it != epsilon_map[state].end(); ++it) {
unsigned new_state = *it;
if (closure.find(new_state) == closure.end()) {
closure.insert(new_state);
worklist.push_back(new_state);
}
}
}
}
}
bool nfa::matches(zstring input) {
/*
* Keep a set of all states the NFA can currently be in.
* Initially this is the e-closure of m_start_state
* For each character A in the input string,
* the set of next states contains
* all states in transition_map[S][A] for each S in current_states,
* and all states in epsilon_map[S] for each S in current_states.
* After consuming the entire input string,
* the match is successful iff current_states contains m_end_state.
*/
std::set<unsigned> current_states;
epsilon_closure(m_start_state, current_states);
for (unsigned i = 0; i < input.length(); ++i) {
char A = (char)input[i];
std::set<unsigned> next_states;
for (std::set<unsigned>::iterator it = current_states.begin();
it != current_states.end(); ++it) {
unsigned S = *it;
// check transition_map
if (transition_map[S].find(A) != transition_map[S].end()) {
next_states.insert(transition_map[S][A]);
}
}
// take e-closure over next_states to compute the actual next_states
std::set<unsigned> epsilon_next_states;
for (std::set<unsigned>::iterator it = next_states.begin(); it != next_states.end(); ++it) {
unsigned S = *it;
std::set<unsigned> closure;
epsilon_closure(S, closure);
epsilon_next_states.insert(closure.begin(), closure.end());
}
current_states = epsilon_next_states;
}
if (current_states.find(m_end_state) != current_states.end()) {
return true;
} else {
return false;
}
}
void theory_str::check_regex_in(expr * nn1, expr * nn2) {
context & ctx = get_context();
ast_manager & m = get_manager();
expr_ref_vector eqNodeSet(m);
expr * constStr_1 = collect_eq_nodes(nn1, eqNodeSet);
expr * constStr_2 = collect_eq_nodes(nn2, eqNodeSet);
expr * constStr = (constStr_1 != NULL) ? constStr_1 : constStr_2;
if (constStr == NULL) {
return;
} else {
expr_ref_vector::iterator itor = eqNodeSet.begin();
for (; itor != eqNodeSet.end(); itor++) {
if (regex_in_var_reg_str_map.find(*itor) != regex_in_var_reg_str_map.end()) {
std::set<zstring>::iterator strItor = regex_in_var_reg_str_map[*itor].begin();
for (; strItor != regex_in_var_reg_str_map[*itor].end(); strItor++) {
zstring regStr = *strItor;
zstring constStrValue;
u.str.is_string(constStr, constStrValue);
std::pair<expr*, zstring> key1 = std::make_pair(*itor, regStr);
if (regex_in_bool_map.find(key1) != regex_in_bool_map.end()) {
expr * boolVar = regex_in_bool_map[key1]; // actually the RegexIn term
app * a_regexIn = to_app(boolVar);
expr * regexTerm = a_regexIn->get_arg(1);
// TODO figure out regex NFA stuff
if (regex_nfa_cache.find(regexTerm) == regex_nfa_cache.end()) {
TRACE("str", tout << "regex_nfa_cache: cache miss" << std::endl;);
regex_nfa_cache[regexTerm] = nfa(u, regexTerm);
} else {
TRACE("str", tout << "regex_nfa_cache: cache hit" << std::endl;);
}
nfa regexNFA = regex_nfa_cache[regexTerm];
ENSURE(regexNFA.is_valid());
bool matchRes = regexNFA.matches(constStrValue);
TRACE("str", tout << mk_pp(*itor, m) << " in " << regStr << " : " << (matchRes ? "yes" : "no") << std::endl;);
expr_ref implyL(ctx.mk_eq_atom(*itor, constStr), m);
if (matchRes) {
assert_implication(implyL, boolVar);
} else {
assert_implication(implyL, m.mk_not(boolVar));
}
}
}
}
}
}
}
/*
* strArgmt::solve_concat_eq_str()
* Solve concatenations of the form:
* const == Concat(const, X)
* const == Concat(X, const)
*/
void theory_str::solve_concat_eq_str(expr * concat, expr * str) {
ast_manager & m = get_manager();
context & ctx = get_context();
TRACE("str", tout << mk_ismt2_pp(concat, m) << " == " << mk_ismt2_pp(str, m) << std::endl;);
zstring const_str;
if (u.str.is_concat(to_app(concat)) && u.str.is_string(to_app(str), const_str)) {
app * a_concat = to_app(concat);
SASSERT(a_concat->get_num_args() == 2);
expr * a1 = a_concat->get_arg(0);
expr * a2 = a_concat->get_arg(1);
if (const_str.empty()) {
TRACE("str", tout << "quick path: concat == \"\"" << std::endl;);
// assert the following axiom:
// ( (Concat a1 a2) == "" ) -> ( (a1 == "") AND (a2 == "") )
expr_ref premise(ctx.mk_eq_atom(concat, str), m);
expr_ref c1(ctx.mk_eq_atom(a1, str), m);
expr_ref c2(ctx.mk_eq_atom(a2, str), m);
expr_ref conclusion(m.mk_and(c1, c2), m);
assert_implication(premise, conclusion);
return;
}
bool arg1_has_eqc_value = false;
bool arg2_has_eqc_value = false;
expr * arg1 = get_eqc_value(a1, arg1_has_eqc_value);
expr * arg2 = get_eqc_value(a2, arg2_has_eqc_value);
expr_ref newConcat(m);
if (arg1 != a1 || arg2 != a2) {
TRACE("str", tout << "resolved concat argument(s) to eqc string constants" << std::endl;);
int iPos = 0;
expr_ref_vector item1(m);
if (a1 != arg1) {
item1.push_back(ctx.mk_eq_atom(a1, arg1));
iPos += 1;
}
if (a2 != arg2) {
item1.push_back(ctx.mk_eq_atom(a2, arg2));
iPos += 1;
}
expr_ref implyL1(mk_and(item1), m);
newConcat = mk_concat(arg1, arg2);
if (newConcat != str) {
expr_ref implyR1(ctx.mk_eq_atom(concat, newConcat), m);
assert_implication(implyL1, implyR1);
}
} else {
newConcat = concat;
}
if (newConcat == str) {
return;
}
if (!u.str.is_concat(to_app(newConcat))) {
return;
}
if (arg1_has_eqc_value && arg2_has_eqc_value) {
// Case 1: Concat(const, const) == const
TRACE("str", tout << "Case 1: Concat(const, const) == const" << std::endl;);
zstring arg1_str, arg2_str;
u.str.is_string(arg1, arg1_str);
u.str.is_string(arg2, arg2_str);
zstring result_str = arg1_str + arg2_str;
if (result_str != const_str) {
// Inconsistency
TRACE("str", tout << "inconsistency detected: \""
<< arg1_str << "\" + \"" << arg2_str <<
"\" != \"" << const_str << "\"" << "\n";);
expr_ref equality(ctx.mk_eq_atom(concat, str), m);
expr_ref diseq(m.mk_not(equality), m);
assert_axiom(diseq);
return;
}
} else if (!arg1_has_eqc_value && arg2_has_eqc_value) {
// Case 2: Concat(var, const) == const
TRACE("str", tout << "Case 2: Concat(var, const) == const" << std::endl;);
zstring arg2_str;
u.str.is_string(arg2, arg2_str);
unsigned int resultStrLen = const_str.length();
unsigned int arg2StrLen = arg2_str.length();
if (resultStrLen < arg2StrLen) {
// Inconsistency
TRACE("str", tout << "inconsistency detected: \""
<< arg2_str <<
"\" is longer than \"" << const_str << "\","
<< " so cannot be concatenated with anything to form it" << "\n";);
expr_ref equality(ctx.mk_eq_atom(newConcat, str), m);
expr_ref diseq(m.mk_not(equality), m);
assert_axiom(diseq);
return;
} else {
int varStrLen = resultStrLen - arg2StrLen;
zstring firstPart = const_str.extract(0, varStrLen);
zstring secondPart = const_str.extract(varStrLen, arg2StrLen);
if (arg2_str != secondPart) {
// Inconsistency
TRACE("str", tout << "inconsistency detected: "
<< "suffix of concatenation result expected \"" << secondPart << "\", "
<< "actually \"" << arg2_str << "\""
<< "\n";);
expr_ref equality(ctx.mk_eq_atom(newConcat, str), m);
expr_ref diseq(m.mk_not(equality), m);
assert_axiom(diseq);
return;
} else {
expr_ref tmpStrConst(mk_string(firstPart), m);
expr_ref premise(ctx.mk_eq_atom(newConcat, str), m);
expr_ref conclusion(ctx.mk_eq_atom(arg1, tmpStrConst), m);
assert_implication(premise, conclusion);
return;
}
}
} else if (arg1_has_eqc_value && !arg2_has_eqc_value) {
// Case 3: Concat(const, var) == const
TRACE("str", tout << "Case 3: Concat(const, var) == const" << std::endl;);
zstring arg1_str;
u.str.is_string(arg1, arg1_str);
unsigned int resultStrLen = const_str.length();
unsigned int arg1StrLen = arg1_str.length();
if (resultStrLen < arg1StrLen) {
// Inconsistency
TRACE("str", tout << "inconsistency detected: \""
<< arg1_str <<
"\" is longer than \"" << const_str << "\","
<< " so cannot be concatenated with anything to form it" << "\n";);
expr_ref equality(ctx.mk_eq_atom(newConcat, str), m);
expr_ref diseq(m.mk_not(equality), m);
assert_axiom(diseq);
return;
} else {
int varStrLen = resultStrLen - arg1StrLen;
zstring firstPart = const_str.extract(0, arg1StrLen);
zstring secondPart = const_str.extract(arg1StrLen, varStrLen);
if (arg1_str != firstPart) {
// Inconsistency
TRACE("str", tout << "inconsistency detected: "
<< "prefix of concatenation result expected \"" << secondPart << "\", "
<< "actually \"" << arg1_str << "\""
<< "\n";);
expr_ref equality(ctx.mk_eq_atom(newConcat, str), m);
expr_ref diseq(m.mk_not(equality), m);
assert_axiom(diseq);
return;
} else {
expr_ref tmpStrConst(mk_string(secondPart), m);
expr_ref premise(ctx.mk_eq_atom(newConcat, str), m);
expr_ref conclusion(ctx.mk_eq_atom(arg2, tmpStrConst), m);
assert_implication(premise, conclusion);
return;
}
}
} else {
// Case 4: Concat(var, var) == const
TRACE("str", tout << "Case 4: Concat(var, var) == const" << std::endl;);
if (eval_concat(arg1, arg2) == NULL) {
rational arg1Len, arg2Len;
bool arg1Len_exists = get_len_value(arg1, arg1Len);
bool arg2Len_exists = get_len_value(arg2, arg2Len);
rational concatStrLen((unsigned)const_str.length());
if (arg1Len_exists || arg2Len_exists) {
expr_ref ax_l1(ctx.mk_eq_atom(concat, str), m);
expr_ref ax_l2(m);
zstring prefixStr, suffixStr;
if (arg1Len_exists) {
if (arg1Len.is_neg()) {
TRACE("str", tout << "length conflict: arg1Len = " << arg1Len << ", concatStrLen = " << concatStrLen << std::endl;);
expr_ref toAssert(m_autil.mk_ge(mk_strlen(arg1), mk_int(0)), m);
assert_axiom(toAssert);
return;
} else if (arg1Len > concatStrLen) {
TRACE("str", tout << "length conflict: arg1Len = " << arg1Len << ", concatStrLen = " << concatStrLen << std::endl;);
expr_ref ax_r1(m_autil.mk_le(mk_strlen(arg1), mk_int(concatStrLen)), m);
assert_implication(ax_l1, ax_r1);
return;
}
prefixStr = const_str.extract(0, arg1Len.get_unsigned());
rational concat_minus_arg1 = concatStrLen - arg1Len;
suffixStr = const_str.extract(arg1Len.get_unsigned(), concat_minus_arg1.get_unsigned());
ax_l2 = ctx.mk_eq_atom(mk_strlen(arg1), mk_int(arg1Len));
} else {
// arg2's length is available
if (arg2Len.is_neg()) {
TRACE("str", tout << "length conflict: arg2Len = " << arg2Len << ", concatStrLen = " << concatStrLen << std::endl;);
expr_ref toAssert(m_autil.mk_ge(mk_strlen(arg2), mk_int(0)), m);
assert_axiom(toAssert);
return;
} else if (arg2Len > concatStrLen) {
TRACE("str", tout << "length conflict: arg2Len = " << arg2Len << ", concatStrLen = " << concatStrLen << std::endl;);
expr_ref ax_r1(m_autil.mk_le(mk_strlen(arg2), mk_int(concatStrLen)), m);
assert_implication(ax_l1, ax_r1);
return;
}
rational concat_minus_arg2 = concatStrLen - arg2Len;
prefixStr = const_str.extract(0, concat_minus_arg2.get_unsigned());
suffixStr = const_str.extract(concat_minus_arg2.get_unsigned(), arg2Len.get_unsigned());
ax_l2 = ctx.mk_eq_atom(mk_strlen(arg2), mk_int(arg2Len));
}
// consistency check
if (u.str.is_concat(to_app(arg1)) && !can_concat_eq_str(arg1, prefixStr)) {
expr_ref ax_r(m.mk_not(ax_l2), m);
assert_implication(ax_l1, ax_r);
return;
}
if (u.str.is_concat(to_app(arg2)) && !can_concat_eq_str(arg2, suffixStr)) {
expr_ref ax_r(m.mk_not(ax_l2), m);
assert_implication(ax_l1, ax_r);
return;
}
expr_ref_vector r_items(m);
r_items.push_back(ctx.mk_eq_atom(arg1, mk_string(prefixStr)));
r_items.push_back(ctx.mk_eq_atom(arg2, mk_string(suffixStr)));
if (!arg1Len_exists) {
r_items.push_back(ctx.mk_eq_atom(mk_strlen(arg1), mk_int(prefixStr.length())));
}
if (!arg2Len_exists) {
r_items.push_back(ctx.mk_eq_atom(mk_strlen(arg2), mk_int(suffixStr.length())));
}
expr_ref lhs(m.mk_and(ax_l1, ax_l2), m);
expr_ref rhs(mk_and(r_items), m);
assert_implication(lhs, rhs);
} else { /* ! (arg1Len != 1 || arg2Len != 1) */
expr_ref xorFlag(m);
std::pair<expr*, expr*> key1(arg1, arg2);
std::pair<expr*, expr*> key2(arg2, arg1);
// check the entries in this map to make sure they're still in scope
// before we use them.
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry1 = varForBreakConcat.find(key1);
std::map<std::pair<expr*,expr*>, std::map<int, expr*> >::iterator entry2 = varForBreakConcat.find(key2);
bool entry1InScope;
if (entry1 == varForBreakConcat.end()) {
TRACE("str", tout << "key1 no entry" << std::endl;);
entry1InScope = false;
} else {
// OVERRIDE.
entry1InScope = true;
TRACE("str", tout << "key1 entry" << std::endl;);
/*
if (internal_variable_set.find((entry1->second)[0]) == internal_variable_set.end()) {
TRACE("str", tout << "key1 entry not in scope" << std::endl;);
entry1InScope = false;
} else {
TRACE("str", tout << "key1 entry in scope" << std::endl;);
entry1InScope = true;
}
*/
}
bool entry2InScope;
if (entry2 == varForBreakConcat.end()) {
TRACE("str", tout << "key2 no entry" << std::endl;);
entry2InScope = false;
} else {
// OVERRIDE.
entry2InScope = true;
TRACE("str", tout << "key2 entry" << std::endl;);
/*
if (internal_variable_set.find((entry2->second)[0]) == internal_variable_set.end()) {
TRACE("str", tout << "key2 entry not in scope" << std::endl;);
entry2InScope = false;
} else {
TRACE("str", tout << "key2 entry in scope" << std::endl;);
entry2InScope = true;
}
*/
}
TRACE("str", tout << "entry 1 " << (entry1InScope ? "in scope" : "not in scope") << std::endl
<< "entry 2 " << (entry2InScope ? "in scope" : "not in scope") << std::endl;);
if (!entry1InScope && !entry2InScope) {
xorFlag = mk_internal_xor_var();
varForBreakConcat[key1][0] = xorFlag;
} else if (entry1InScope) {
xorFlag = varForBreakConcat[key1][0];
} else { // entry2InScope
xorFlag = varForBreakConcat[key2][0];
}
int concatStrLen = const_str.length();
int and_count = 1;
expr_ref_vector arrangement_disjunction(m);
for (int i = 0; i < concatStrLen + 1; ++i) {
expr_ref_vector and_items(m);
zstring prefixStr = const_str.extract(0, i);
zstring suffixStr = const_str.extract(i, concatStrLen - i);
// skip invalid options
if (u.str.is_concat(to_app(arg1)) && !can_concat_eq_str(arg1, prefixStr)) {
continue;
}
if (u.str.is_concat(to_app(arg2)) && !can_concat_eq_str(arg2, suffixStr)) {
continue;
}
expr_ref prefixAst(mk_string(prefixStr), m);
expr_ref arg1_eq (ctx.mk_eq_atom(arg1, prefixAst), m);
and_items.push_back(arg1_eq);
and_count += 1;
expr_ref suffixAst(mk_string(suffixStr), m);
expr_ref arg2_eq (ctx.mk_eq_atom(arg2, suffixAst), m);
and_items.push_back(arg2_eq);
and_count += 1;
arrangement_disjunction.push_back(mk_and(and_items));
}
expr_ref implyL(ctx.mk_eq_atom(concat, str), m);
expr_ref implyR1(m);
if (arrangement_disjunction.empty()) {
// negate
expr_ref concat_eq_str(ctx.mk_eq_atom(concat, str), m);
expr_ref negate_ast(m.mk_not(concat_eq_str), m);
assert_axiom(negate_ast);
} else {
implyR1 = mk_or(arrangement_disjunction);
if (m_params.m_StrongArrangements) {
expr_ref ax_strong(ctx.mk_eq_atom(implyL, implyR1), m);
assert_axiom(ax_strong);
} else {
assert_implication(implyL, implyR1);
}
generate_mutual_exclusion(arrangement_disjunction);
}
} /* (arg1Len != 1 || arg2Len != 1) */
} /* if (Concat(arg1, arg2) == NULL) */
}
}
}
expr_ref theory_str::set_up_finite_model_test(expr * lhs, expr * rhs) {
context & ctx = get_context();
ast_manager & m = get_manager();
TRACE("str", tout << "activating finite model testing for overlapping concats "
<< mk_pp(lhs, m) << " and " << mk_pp(rhs, m) << std::endl;);
std::map<expr*, int> concatMap;
std::map<expr*, int> unrollMap;
std::map<expr*, int> varMap;
classify_ast_by_type(lhs, varMap, concatMap, unrollMap);
classify_ast_by_type(rhs, varMap, concatMap, unrollMap);
TRACE("str", tout << "found vars:";
for (std::map<expr*,int>::iterator it = varMap.begin(); it != varMap.end(); ++it) {
tout << " " << mk_pp(it->first, m);
}
tout << std::endl;
);
expr_ref testvar(mk_str_var("finiteModelTest"), m);
m_trail.push_back(testvar);
ptr_vector<expr> varlist;
for (std::map<expr*, int>::iterator it = varMap.begin(); it != varMap.end(); ++it) {
expr * v = it->first;
varlist.push_back(v);
}
// make things easy for the core wrt. testvar
expr_ref t1(ctx.mk_eq_atom(testvar, mk_string("")), m);
expr_ref t_yes(ctx.mk_eq_atom(testvar, mk_string("yes")), m);
expr_ref testvaraxiom(m.mk_or(t1, t_yes), m);
assert_axiom(testvaraxiom);
finite_model_test_varlists.insert(testvar, varlist);
m_trail_stack.push(insert_obj_map<theory_str, expr, ptr_vector<expr> >(finite_model_test_varlists, testvar) );
return t_yes;
}
void theory_str::finite_model_test(expr * testvar, expr * str) {
context & ctx = get_context();
ast_manager & m = get_manager();
zstring s;
if (!u.str.is_string(str, s)) return;
if (s == "yes") {
TRACE("str", tout << "start finite model test for " << mk_pp(testvar, m) << std::endl;);
ptr_vector<expr> & vars = finite_model_test_varlists[testvar];
for (ptr_vector<expr>::iterator it = vars.begin(); it != vars.end(); ++it) {
expr * v = *it;
bool v_has_eqc = false;
get_eqc_value(v, v_has_eqc);
if (v_has_eqc) {
TRACE("str", tout << "variable " << mk_pp(v,m) << " already equivalent to a string constant" << std::endl;);
continue;
}
// check for any sort of existing length tester we might interfere with
if (m_params.m_UseBinarySearch) {
if (binary_search_len_tester_stack.contains(v) && !binary_search_len_tester_stack[v].empty()) {
TRACE("str", tout << "already found existing length testers for " << mk_pp(v, m) << std::endl;);
continue;
} else {
// start binary search as normal
expr_ref implLhs(ctx.mk_eq_atom(testvar, str), m);
expr_ref implRhs(binary_search_length_test(v, NULL, ""), m);
assert_implication(implLhs, implRhs);
}
} else {
bool map_effectively_empty = false;
if (!fvar_len_count_map.contains(v)) {
map_effectively_empty = true;
}
if (!map_effectively_empty) {
map_effectively_empty = true;
ptr_vector<expr> indicator_set = fvar_lenTester_map[v];
for (ptr_vector<expr>::iterator it = indicator_set.begin(); it != indicator_set.end(); ++it) {
expr * indicator = *it;
if (internal_variable_set.find(indicator) != internal_variable_set.end()) {
map_effectively_empty = false;
break;
}
}
}
if (map_effectively_empty) {
TRACE("str", tout << "no existing length testers for " << mk_pp(v, m) << std::endl;);
rational v_len;
rational v_lower_bound;
rational v_upper_bound;
expr_ref vLengthExpr(mk_strlen(v), m);
if (get_len_value(v, v_len)) {
TRACE("str", tout << "length = " << v_len.to_string() << std::endl;);
v_lower_bound = v_len;
v_upper_bound = v_len;
} else {
bool lower_bound_exists = lower_bound(vLengthExpr, v_lower_bound);
bool upper_bound_exists = upper_bound(vLengthExpr, v_upper_bound);
TRACE("str", tout << "bounds = [" << (lower_bound_exists?v_lower_bound.to_string():"?")
<< ".." << (upper_bound_exists?v_upper_bound.to_string():"?") << "]" << std::endl;);
// make sure the bounds are non-negative
if (lower_bound_exists && v_lower_bound.is_neg()) {
v_lower_bound = rational::zero();
}
if (upper_bound_exists && v_upper_bound.is_neg()) {
v_upper_bound = rational::zero();
}
if (lower_bound_exists && upper_bound_exists) {
// easiest case. we will search within these bounds
} else if (upper_bound_exists && !lower_bound_exists) {
// search between 0 and the upper bound
v_lower_bound == rational::zero();
} else if (lower_bound_exists && !upper_bound_exists) {
// check some finite portion of the search space
v_upper_bound = v_lower_bound + rational(10);
} else {
// no bounds information
v_lower_bound = rational::zero();
v_upper_bound = v_lower_bound + rational(10);
}
}
// now create a fake length tester over this finite disjunction of lengths
fvar_len_count_map[v] = 1;
unsigned int testNum = fvar_len_count_map[v];
expr_ref indicator(mk_internal_lenTest_var(v, testNum), m);
SASSERT(indicator);
m_trail.push_back(indicator);
fvar_lenTester_map[v].shrink(0);
fvar_lenTester_map[v].push_back(indicator);
lenTester_fvar_map[indicator] = v;
expr_ref_vector orList(m);
expr_ref_vector andList(m);
for (rational l = v_lower_bound; l <= v_upper_bound; l += rational::one()) {
zstring lStr = zstring(l.to_string().c_str());
expr_ref str_indicator(mk_string(lStr), m);
expr_ref or_expr(ctx.mk_eq_atom(indicator, str_indicator), m);
orList.push_back(or_expr);
expr_ref and_expr(ctx.mk_eq_atom(or_expr, ctx.mk_eq_atom(vLengthExpr, m_autil.mk_numeral(l, true))), m);
andList.push_back(and_expr);
}
andList.push_back(mk_or(orList));
expr_ref implLhs(ctx.mk_eq_atom(testvar, str), m);
expr_ref implRhs(mk_and(andList), m);
assert_implication(implLhs, implRhs);
} else {
TRACE("str", tout << "already found existing length testers for " << mk_pp(v, m) << std::endl;);
continue;
}
}
} // foreach (v in vars)
} // (s == "yes")
}
void theory_str::more_len_tests(expr * lenTester, zstring lenTesterValue) {
ast_manager & m = get_manager();
if (lenTester_fvar_map.contains(lenTester)) {
expr * fVar = lenTester_fvar_map[lenTester];
expr * toAssert = gen_len_val_options_for_free_var(fVar, lenTester, lenTesterValue);
TRACE("str", tout << "asserting more length tests for free variable " << mk_ismt2_pp(fVar, m) << std::endl;);
if (toAssert != NULL) {
assert_axiom(toAssert);
}
}
}
void theory_str::more_value_tests(expr * valTester, zstring valTesterValue) {
ast_manager & m = get_manager();
expr * fVar = valueTester_fvar_map[valTester];
if (m_params.m_UseBinarySearch) {
if (!binary_search_len_tester_stack.contains(fVar) || binary_search_len_tester_stack[fVar].empty()) {
TRACE("str", tout << "WARNING: no active length testers for " << mk_pp(fVar, m) << std::endl;);
NOT_IMPLEMENTED_YET();
}
expr * effectiveLenInd = binary_search_len_tester_stack[fVar].back();
bool hasEqcValue;
expr * len_indicator_value = get_eqc_value(effectiveLenInd, hasEqcValue);
if (!hasEqcValue) {
TRACE("str", tout << "WARNING: length tester " << mk_pp(effectiveLenInd, m) << " at top of stack for " << mk_pp(fVar, m) << " has no EQC value" << std::endl;);
} else {
// safety check
zstring effectiveLenIndiStr;
u.str.is_string(len_indicator_value, effectiveLenIndiStr);
if (effectiveLenIndiStr == "more" || effectiveLenIndiStr == "less") {
TRACE("str", tout << "ERROR: illegal state -- requesting 'more value tests' but a length tester is not yet concrete!" << std::endl;);
UNREACHABLE();
}
expr * valueAssert = gen_free_var_options(fVar, effectiveLenInd, effectiveLenIndiStr, valTester, valTesterValue);
TRACE("str", tout << "asserting more value tests for free variable " << mk_ismt2_pp(fVar, m) << std::endl;);
if (valueAssert != NULL) {
assert_axiom(valueAssert);
}
}
} else {
int lenTesterCount = fvar_lenTester_map[fVar].size();
expr * effectiveLenInd = NULL;
zstring effectiveLenIndiStr = "";
for (int i = 0; i < lenTesterCount; ++i) {
expr * len_indicator_pre = fvar_lenTester_map[fVar][i];
bool indicatorHasEqcValue = false;
expr * len_indicator_value = get_eqc_value(len_indicator_pre, indicatorHasEqcValue);
if (indicatorHasEqcValue) {
zstring len_pIndiStr;
u.str.is_string(len_indicator_value, len_pIndiStr);
if (len_pIndiStr != "more") {
effectiveLenInd = len_indicator_pre;
effectiveLenIndiStr = len_pIndiStr;
break;
}
}
}
expr * valueAssert = gen_free_var_options(fVar, effectiveLenInd, effectiveLenIndiStr, valTester, valTesterValue);
TRACE("str", tout << "asserting more value tests for free variable " << mk_ismt2_pp(fVar, m) << std::endl;);
if (valueAssert != NULL) {
assert_axiom(valueAssert);
}
}
}
bool theory_str::free_var_attempt(expr * nn1, expr * nn2) {
ast_manager & m = get_manager();
zstring nn2_str;
if (internal_lenTest_vars.contains(nn1) && u.str.is_string(nn2, nn2_str)) {
TRACE("str", tout << "acting on equivalence between length tester var " << mk_ismt2_pp(nn1, m)
<< " and constant " << mk_ismt2_pp(nn2, m) << std::endl;);
more_len_tests(nn1, nn2_str);
return true;
} else if (internal_valTest_vars.contains(nn1) && u.str.is_string(nn2, nn2_str)) {
if (nn2_str == "more") {
TRACE("str", tout << "acting on equivalence between value var " << mk_ismt2_pp(nn1, m)
<< " and constant " << mk_ismt2_pp(nn2, m) << std::endl;);
more_value_tests(nn1, nn2_str);
}
return true;
} else if (internal_unrollTest_vars.contains(nn1)) {
return true;
} else {
return false;
}
}
void theory_str::handle_equality(expr * lhs, expr * rhs) {
ast_manager & m = get_manager();
context & ctx = get_context();
// both terms must be of sort String
sort * lhs_sort = m.get_sort(lhs);
sort * rhs_sort = m.get_sort(rhs);
sort * str_sort = u.str.mk_string_sort();
if (lhs_sort != str_sort || rhs_sort != str_sort) {
TRACE("str", tout << "skip equality: not String sort" << std::endl;);
return;
}
/* // temporarily disabled, we are borrowing these testers for something else
if (m_params.m_FiniteOverlapModels && !finite_model_test_varlists.empty()) {
if (finite_model_test_varlists.contains(lhs)) {
finite_model_test(lhs, rhs); return;
} else if (finite_model_test_varlists.contains(rhs)) {
finite_model_test(rhs, lhs); return;
}
}
*/
if (free_var_attempt(lhs, rhs) || free_var_attempt(rhs, lhs)) {
return;
}
if (u.str.is_concat(to_app(lhs)) && u.str.is_concat(to_app(rhs))) {
bool nn1HasEqcValue = false;
bool nn2HasEqcValue = false;
expr * nn1_value = get_eqc_value(lhs, nn1HasEqcValue);
expr * nn2_value = get_eqc_value(rhs, nn2HasEqcValue);
if (nn1HasEqcValue && !nn2HasEqcValue) {
simplify_parent(rhs, nn1_value);
}
if (!nn1HasEqcValue && nn2HasEqcValue) {
simplify_parent(lhs, nn2_value);
}
expr * nn1_arg0 = to_app(lhs)->get_arg(0);
expr * nn1_arg1 = to_app(lhs)->get_arg(1);
expr * nn2_arg0 = to_app(rhs)->get_arg(0);
expr * nn2_arg1 = to_app(rhs)->get_arg(1);
if (nn1_arg0 == nn2_arg0 && in_same_eqc(nn1_arg1, nn2_arg1)) {
TRACE("str", tout << "skip: lhs arg0 == rhs arg0" << std::endl;);
return;
}
if (nn1_arg1 == nn2_arg1 && in_same_eqc(nn1_arg0, nn2_arg0)) {
TRACE("str", tout << "skip: lhs arg1 == rhs arg1" << std::endl;);
return;
}
}
if (opt_DeferEQCConsistencyCheck) {
TRACE("str", tout << "opt_DeferEQCConsistencyCheck is set; deferring new_eq_check call" << std::endl;);
} else {
// newEqCheck() -- check consistency wrt. existing equivalence classes
if (!new_eq_check(lhs, rhs)) {
return;
}
}
// BEGIN new_eq_handler() in strTheory
{
rational nn1Len, nn2Len;
bool nn1Len_exists = get_len_value(lhs, nn1Len);
bool nn2Len_exists = get_len_value(rhs, nn2Len);
expr * emptyStr = mk_string("");
if (nn1Len_exists && nn1Len.is_zero()) {
if (!in_same_eqc(lhs, emptyStr) && rhs != emptyStr) {
expr_ref eql(ctx.mk_eq_atom(mk_strlen(lhs), mk_int(0)), m);
expr_ref eqr(ctx.mk_eq_atom(lhs, emptyStr), m);
expr_ref toAssert(ctx.mk_eq_atom(eql, eqr), m);
assert_axiom(toAssert);
}
}
if (nn2Len_exists && nn2Len.is_zero()) {
if (!in_same_eqc(rhs, emptyStr) && lhs != emptyStr) {
expr_ref eql(ctx.mk_eq_atom(mk_strlen(rhs), mk_int(0)), m);
expr_ref eqr(ctx.mk_eq_atom(rhs, emptyStr), m);
expr_ref toAssert(ctx.mk_eq_atom(eql, eqr), m);
assert_axiom(toAssert);
}
}
}
instantiate_str_eq_length_axiom(ctx.get_enode(lhs), ctx.get_enode(rhs));
// group terms by equivalence class (groupNodeInEqc())
std::set<expr*> eqc_concat_lhs;
std::set<expr*> eqc_var_lhs;
std::set<expr*> eqc_const_lhs;
group_terms_by_eqc(lhs, eqc_concat_lhs, eqc_var_lhs, eqc_const_lhs);
std::set<expr*> eqc_concat_rhs;
std::set<expr*> eqc_var_rhs;
std::set<expr*> eqc_const_rhs;
group_terms_by_eqc(rhs, eqc_concat_rhs, eqc_var_rhs, eqc_const_rhs);
TRACE("str",
tout << "lhs eqc:" << std::endl;
tout << "Concats:" << std::endl;
for (std::set<expr*>::iterator it = eqc_concat_lhs.begin(); it != eqc_concat_lhs.end(); ++it) {
expr * ex = *it;
tout << mk_ismt2_pp(ex, get_manager()) << std::endl;
}
tout << "Variables:" << std::endl;
for (std::set<expr*>::iterator it = eqc_var_lhs.begin(); it != eqc_var_lhs.end(); ++it) {
expr * ex = *it;
tout << mk_ismt2_pp(ex, get_manager()) << std::endl;
}
tout << "Constants:" << std::endl;
for (std::set<expr*>::iterator it = eqc_const_lhs.begin(); it != eqc_const_lhs.end(); ++it) {
expr * ex = *it;
tout << mk_ismt2_pp(ex, get_manager()) << std::endl;
}
tout << "rhs eqc:" << std::endl;
tout << "Concats:" << std::endl;
for (std::set<expr*>::iterator it = eqc_concat_rhs.begin(); it != eqc_concat_rhs.end(); ++it) {
expr * ex = *it;
tout << mk_ismt2_pp(ex, get_manager()) << std::endl;
}
tout << "Variables:" << std::endl;
for (std::set<expr*>::iterator it = eqc_var_rhs.begin(); it != eqc_var_rhs.end(); ++it) {
expr * ex = *it;
tout << mk_ismt2_pp(ex, get_manager()) << std::endl;
}
tout << "Constants:" << std::endl;
for (std::set<expr*>::iterator it = eqc_const_rhs.begin(); it != eqc_const_rhs.end(); ++it) {
expr * ex = *it;
tout << mk_ismt2_pp(ex, get_manager()) << std::endl;
}
);
// step 1: Concat == Concat
int hasCommon = 0;
if (eqc_concat_lhs.size() != 0 && eqc_concat_rhs.size() != 0) {
std::set<expr*>::iterator itor1 = eqc_concat_lhs.begin();
std::set<expr*>::iterator itor2 = eqc_concat_rhs.begin();
for (; itor1 != eqc_concat_lhs.end(); itor1++) {
if (eqc_concat_rhs.find(*itor1) != eqc_concat_rhs.end()) {
hasCommon = 1;
break;
}
}
for (; itor2 != eqc_concat_rhs.end(); itor2++) {
if (eqc_concat_lhs.find(*itor2) != eqc_concat_lhs.end()) {
hasCommon = 1;
break;
}
}
if (hasCommon == 0) {
if (opt_ConcatOverlapAvoid) {
bool found = false;
// check each pair and take the first ones that won't immediately overlap
for (itor1 = eqc_concat_lhs.begin(); itor1 != eqc_concat_lhs.end() && !found; ++itor1) {
expr * concat_lhs = *itor1;
for (itor2 = eqc_concat_rhs.begin(); itor2 != eqc_concat_rhs.end() && !found; ++itor2) {
expr * concat_rhs = *itor2;
if (will_result_in_overlap(concat_lhs, concat_rhs)) {
TRACE("str", tout << "Concats " << mk_pp(concat_lhs, m) << " and "
<< mk_pp(concat_rhs, m) << " will result in overlap; skipping." << std::endl;);
} else {
TRACE("str", tout << "Concats " << mk_pp(concat_lhs, m) << " and "
<< mk_pp(concat_rhs, m) << " won't overlap. Simplifying here." << std::endl;);
simplify_concat_equality(concat_lhs, concat_rhs);
found = true;
break;
}
}
}
if (!found) {
TRACE("str", tout << "All pairs of concats expected to overlap, falling back." << std::endl;);
simplify_concat_equality(*(eqc_concat_lhs.begin()), *(eqc_concat_rhs.begin()));
}
} else {
// default behaviour
simplify_concat_equality(*(eqc_concat_lhs.begin()), *(eqc_concat_rhs.begin()));
}
}
}
// step 2: Concat == Constant
if (eqc_const_lhs.size() != 0) {
expr * conStr = *(eqc_const_lhs.begin());
std::set<expr*>::iterator itor2 = eqc_concat_rhs.begin();
for (; itor2 != eqc_concat_rhs.end(); itor2++) {
solve_concat_eq_str(*itor2, conStr);
}
} else if (eqc_const_rhs.size() != 0) {
expr* conStr = *(eqc_const_rhs.begin());
std::set<expr*>::iterator itor1 = eqc_concat_lhs.begin();
for (; itor1 != eqc_concat_lhs.end(); itor1++) {
solve_concat_eq_str(*itor1, conStr);
}
}
// simplify parents wrt. the equivalence class of both sides
bool nn1HasEqcValue = false;
bool nn2HasEqcValue = false;
// we want the Z3str2 eqc check here...
expr * nn1_value = z3str2_get_eqc_value(lhs, nn1HasEqcValue);
expr * nn2_value = z3str2_get_eqc_value(rhs, nn2HasEqcValue);
if (nn1HasEqcValue && !nn2HasEqcValue) {
simplify_parent(rhs, nn1_value);
}
if (!nn1HasEqcValue && nn2HasEqcValue) {
simplify_parent(lhs, nn2_value);
}
expr * nn1EqConst = NULL;
std::set<expr*> nn1EqUnrollFuncs;
get_eqc_allUnroll(lhs, nn1EqConst, nn1EqUnrollFuncs);
expr * nn2EqConst = NULL;
std::set<expr*> nn2EqUnrollFuncs;
get_eqc_allUnroll(rhs, nn2EqConst, nn2EqUnrollFuncs);
if (nn2EqConst != NULL) {
for (std::set<expr*>::iterator itor1 = nn1EqUnrollFuncs.begin(); itor1 != nn1EqUnrollFuncs.end(); itor1++) {
process_unroll_eq_const_str(*itor1, nn2EqConst);
}
}
if (nn1EqConst != NULL) {
for (std::set<expr*>::iterator itor2 = nn2EqUnrollFuncs.begin(); itor2 != nn2EqUnrollFuncs.end(); itor2++) {
process_unroll_eq_const_str(*itor2, nn1EqConst);
}
}
}
void theory_str::set_up_axioms(expr * ex) {
ast_manager & m = get_manager();
context & ctx = get_context();
sort * ex_sort = m.get_sort(ex);
sort * str_sort = u.str.mk_string_sort();
sort * bool_sort = m.mk_bool_sort();
family_id m_arith_fid = m.mk_family_id("arith");
sort * int_sort = m.mk_sort(m_arith_fid, INT_SORT);
if (ex_sort == str_sort) {
TRACE("str", tout << "setting up axioms for " << mk_ismt2_pp(ex, get_manager()) <<
": expr is of sort String" << std::endl;);
// set up basic string axioms
enode * n = ctx.get_enode(ex);
SASSERT(n);
m_basicstr_axiom_todo.push_back(n);
TRACE("str", tout << "add " << mk_pp(ex, m) << " to m_basicstr_axiom_todo" << std::endl;);
if (is_app(ex)) {
app * ap = to_app(ex);
if (u.str.is_concat(ap)) {
// if ex is a concat, set up concat axioms later
m_concat_axiom_todo.push_back(n);
// we also want to check whether we can eval this concat,
// in case the rewriter did not totally finish with this term
m_concat_eval_todo.push_back(n);
} else if (u.str.is_length(ap)) {
// if the argument is a variable,
// keep track of this for later, we'll need it during model gen
expr * var = ap->get_arg(0);
app * aVar = to_app(var);
if (aVar->get_num_args() == 0 && !u.str.is_string(aVar)) {
input_var_in_len.insert(var);
}
} else if (u.str.is_at(ap) || u.str.is_extract(ap) || u.str.is_replace(ap)) {
m_library_aware_axiom_todo.push_back(n);
} else if (u.str.is_itos(ap)) {
TRACE("str", tout << "found string-integer conversion term: " << mk_pp(ex, get_manager()) << std::endl;);
string_int_conversion_terms.push_back(ap);
m_library_aware_axiom_todo.push_back(n);
} else if (ap->get_num_args() == 0 && !u.str.is_string(ap)) {
// if ex is a variable, add it to our list of variables
TRACE("str", tout << "tracking variable " << mk_ismt2_pp(ap, get_manager()) << std::endl;);
variable_set.insert(ex);
ctx.mark_as_relevant(ex);
// this might help??
theory_var v = mk_var(n);
TRACE("str", tout << "variable " << mk_ismt2_pp(ap, get_manager()) << " is #" << v << std::endl;);
}
}
} else if (ex_sort == bool_sort) {
TRACE("str", tout << "setting up axioms for " << mk_ismt2_pp(ex, get_manager()) <<
": expr is of sort Bool" << std::endl;);
// set up axioms for boolean terms
ensure_enode(ex);
if (ctx.e_internalized(ex)) {
enode * n = ctx.get_enode(ex);
SASSERT(n);
if (is_app(ex)) {
app * ap = to_app(ex);
if (u.str.is_prefix(ap) || u.str.is_suffix(ap) || u.str.is_contains(ap) || u.str.is_in_re(ap)) {
m_library_aware_axiom_todo.push_back(n);
}
}
} else {
TRACE("str", tout << "WARNING: Bool term " << mk_ismt2_pp(ex, get_manager()) << " not internalized. Delaying axiom setup to prevent a crash." << std::endl;);
ENSURE(!search_started); // infinite loop prevention
m_delayed_axiom_setup_terms.push_back(ex);
return;
}
} else if (ex_sort == int_sort) {
TRACE("str", tout << "setting up axioms for " << mk_ismt2_pp(ex, get_manager()) <<
": expr is of sort Int" << std::endl;);
// set up axioms for integer terms
enode * n = ensure_enode(ex);
SASSERT(n);
if (is_app(ex)) {
app * ap = to_app(ex);
// TODO indexof2/lastindexof
if (u.str.is_index(ap) /* || is_Indexof2(ap) || is_LastIndexof(ap) */) {
m_library_aware_axiom_todo.push_back(n);
} else if (u.str.is_stoi(ap)) {
TRACE("str", tout << "found string-integer conversion term: " << mk_pp(ex, get_manager()) << std::endl;);
string_int_conversion_terms.push_back(ap);
m_library_aware_axiom_todo.push_back(n);
}
}
} else {
TRACE("str", tout << "setting up axioms for " << mk_ismt2_pp(ex, get_manager()) <<
": expr is of wrong sort, ignoring" << std::endl;);
}
// if expr is an application, recursively inspect all arguments
if (is_app(ex)) {
app * term = (app*)ex;
unsigned num_args = term->get_num_args();
for (unsigned i = 0; i < num_args; i++) {
set_up_axioms(term->get_arg(i));
}
}
}
void theory_str::add_theory_assumptions(expr_ref_vector & assumptions) {
TRACE("str", tout << "add overlap assumption for theory_str" << std::endl;);
const char* strOverlap = "!!TheoryStrOverlapAssumption!!";
seq_util m_sequtil(get_manager());
sort * s = get_manager().mk_bool_sort();
m_theoryStrOverlapAssumption_term = expr_ref(mk_fresh_const(strOverlap, s), get_manager());
assumptions.push_back(get_manager().mk_not(m_theoryStrOverlapAssumption_term));
}
lbool theory_str::validate_unsat_core(expr_ref_vector & unsat_core) {
app * target_term = to_app(get_manager().mk_not(m_theoryStrOverlapAssumption_term));
get_context().internalize(target_term, false);
for (unsigned i = 0; i < unsat_core.size(); ++i) {
app * core_term = to_app(unsat_core.get(i));
// not sure if this is the correct way to compare terms in this context
enode * e1;
enode * e2;
e1 = get_context().get_enode(target_term);
e2 = get_context().get_enode(core_term);
if (e1 == e2) {
TRACE("str", tout << "overlap detected in unsat core, changing UNSAT to UNKNOWN" << std::endl;);
return l_undef;
}
}
return l_false;
}
void theory_str::init_search_eh() {
ast_manager & m = get_manager();
context & ctx = get_context();
TRACE("str",
tout << "dumping all asserted formulas:" << std::endl;
unsigned nFormulas = ctx.get_num_asserted_formulas();
for (unsigned i = 0; i < nFormulas; ++i) {
expr * ex = ctx.get_asserted_formula(i);
tout << mk_ismt2_pp(ex, m) << (ctx.is_relevant(ex) ? " (rel)" : " (NOT REL)") << std::endl;
}
);
/*
* Recursive descent through all asserted formulas to set up axioms.
* Note that this is just the input structure and not necessarily things
* that we know to be true or false. We're just doing this to see
* which terms are explicitly mentioned.
*/
unsigned nFormulas = ctx.get_num_asserted_formulas();
for (unsigned i = 0; i < nFormulas; ++i) {
expr * ex = ctx.get_asserted_formula(i);
set_up_axioms(ex);
}
/*
* Similar recursive descent, except over all initially assigned terms.
* This is done to find equalities between terms, etc. that we otherwise
* might not get a chance to see.
*/
/*
expr_ref_vector assignments(m);
ctx.get_assignments(assignments);
for (expr_ref_vector::iterator i = assignments.begin(); i != assignments.end(); ++i) {
expr * ex = *i;
if (m.is_eq(ex)) {
TRACE("str", tout << "processing assignment " << mk_ismt2_pp(ex, m) <<
": expr is equality" << std::endl;);
app * eq = (app*)ex;
SASSERT(eq->get_num_args() == 2);
expr * lhs = eq->get_arg(0);
expr * rhs = eq->get_arg(1);
enode * e_lhs = ctx.get_enode(lhs);
enode * e_rhs = ctx.get_enode(rhs);
std::pair<enode*,enode*> eq_pair(e_lhs, e_rhs);
m_str_eq_todo.push_back(eq_pair);
} else {
TRACE("str", tout << "processing assignment " << mk_ismt2_pp(ex, m)
<< ": expr ignored" << std::endl;);
}
}
*/
// this might be cheating but we need to make sure that certain maps are populated
// before the first call to new_eq_eh()
propagate();
TRACE("str", tout << "search started" << std::endl;);
search_started = true;
}
void theory_str::new_eq_eh(theory_var x, theory_var y) {
//TRACE("str", tout << "new eq: v#" << x << " = v#" << y << std::endl;);
TRACE("str", tout << "new eq: " << mk_ismt2_pp(get_enode(x)->get_owner(), get_manager()) << " = " <<
mk_ismt2_pp(get_enode(y)->get_owner(), get_manager()) << std::endl;);
/*
if (m_find.find(x) == m_find.find(y)) {
return;
}
*/
handle_equality(get_enode(x)->get_owner(), get_enode(y)->get_owner());
// replicate Z3str2 behaviour: merge eqc **AFTER** handle_equality
m_find.merge(x, y);
}
void theory_str::new_diseq_eh(theory_var x, theory_var y) {
//TRACE("str", tout << "new diseq: v#" << x << " != v#" << y << std::endl;);
TRACE("str", tout << "new diseq: " << mk_ismt2_pp(get_enode(x)->get_owner(), get_manager()) << " != " <<
mk_ismt2_pp(get_enode(y)->get_owner(), get_manager()) << std::endl;);
}
void theory_str::relevant_eh(app * n) {
TRACE("str", tout << "relevant: " << mk_ismt2_pp(n, get_manager()) << std::endl;);
}
void theory_str::assign_eh(bool_var v, bool is_true) {
context & ctx = get_context();
TRACE("str", tout << "assert: v" << v << " #" << ctx.bool_var2expr(v)->get_id() << " is_true: " << is_true << std::endl;);
}
void theory_str::push_scope_eh() {
theory::push_scope_eh();
m_trail_stack.push_scope();
sLevel += 1;
TRACE("str", tout << "push to " << sLevel << std::endl;);
TRACE_CODE(if (is_trace_enabled("t_str_dump_assign_on_scope_change")) { dump_assignments(); });
}
void theory_str::recursive_check_variable_scope(expr * ex) {
ast_manager & m = get_manager();
if (is_app(ex)) {
app * a = to_app(ex);
if (a->get_num_args() == 0) {
// we only care about string variables
sort * s = m.get_sort(ex);
sort * string_sort = u.str.mk_string_sort();
if (s != string_sort) {
return;
}
// base case: string constant / var
if (u.str.is_string(a)) {
return;
} else {
// assume var
if (variable_set.find(ex) == variable_set.end()
&& internal_variable_set.find(ex) == internal_variable_set.end()) {
TRACE("str", tout << "WARNING: possible reference to out-of-scope variable " << mk_pp(ex, m) << std::endl;);
}
}
} else {
for (unsigned i = 0; i < a->get_num_args(); ++i) {
recursive_check_variable_scope(a->get_arg(i));
}
}
}
}
void theory_str::check_variable_scope() {
if (!opt_CheckVariableScope) {
return;
}
if (!is_trace_enabled("t_str_detail")) {
return;
}
TRACE("str", tout << "checking scopes of variables in the current assignment" << std::endl;);
context & ctx = get_context();
ast_manager & m = get_manager();
expr_ref_vector assignments(m);
ctx.get_assignments(assignments);
for (expr_ref_vector::iterator i = assignments.begin(); i != assignments.end(); ++i) {
expr * ex = *i;
recursive_check_variable_scope(ex);
}
}
void theory_str::pop_scope_eh(unsigned num_scopes) {
sLevel -= num_scopes;
TRACE("str", tout << "pop " << num_scopes << " to " << sLevel << std::endl;);
ast_manager & m = get_manager();
TRACE_CODE(if (is_trace_enabled("t_str_dump_assign_on_scope_change")) { dump_assignments(); });
// list of expr* to remove from cut_var_map
ptr_vector<expr> cutvarmap_removes;
obj_map<expr, std::stack<T_cut *> >::iterator varItor = cut_var_map.begin();
while (varItor != cut_var_map.end()) {
expr * e = varItor->m_key;
std::stack<T_cut*> & val = cut_var_map[varItor->m_key];
while ((val.size() > 0) && (val.top()->level != 0) && (val.top()->level >= sLevel)) {
TRACE("str", tout << "remove cut info for " << mk_pp(e, m) << std::endl; print_cut_var(e, tout););
// T_cut * aCut = val.top();
val.pop();
// dealloc(aCut);
}
if (val.size() == 0) {
cutvarmap_removes.insert(varItor->m_key);
}
varItor++;
}
if (!cutvarmap_removes.empty()) {
ptr_vector<expr>::iterator it = cutvarmap_removes.begin();
for (; it != cutvarmap_removes.end(); ++it) {
expr * ex = *it;
cut_var_map.remove(ex);
}
}
ptr_vector<enode> new_m_basicstr;
for (ptr_vector<enode>::iterator it = m_basicstr_axiom_todo.begin(); it != m_basicstr_axiom_todo.end(); ++it) {
enode * e = *it;
app * a = e->get_owner();
TRACE("str", tout << "consider deleting " << mk_pp(a, get_manager())
<< ", enode scope level is " << e->get_iscope_lvl()
<< std::endl;);
if (e->get_iscope_lvl() <= (unsigned)sLevel) {
new_m_basicstr.push_back(e);
}
}
m_basicstr_axiom_todo.reset();
m_basicstr_axiom_todo = new_m_basicstr;
m_trail_stack.pop_scope(num_scopes);
theory::pop_scope_eh(num_scopes);
//check_variable_scope();
}
void theory_str::dump_assignments() {
TRACE_CODE(
ast_manager & m = get_manager();
context & ctx = get_context();
tout << "dumping all assignments:" << std::endl;
expr_ref_vector assignments(m);
ctx.get_assignments(assignments);
for (expr_ref_vector::iterator i = assignments.begin(); i != assignments.end(); ++i) {
expr * ex = *i;
tout << mk_ismt2_pp(ex, m) << (ctx.is_relevant(ex) ? "" : " (NOT REL)") << std::endl;
}
);
}
void theory_str::classify_ast_by_type(expr * node, std::map<expr*, int> & varMap,
std::map<expr*, int> & concatMap, std::map<expr*, int> & unrollMap) {
// check whether the node is a string variable;
// testing set membership here bypasses several expensive checks.
// note that internal variables don't count if they're only length tester / value tester vars.
if (variable_set.find(node) != variable_set.end()
&& internal_lenTest_vars.find(node) == internal_lenTest_vars.end()
&& internal_valTest_vars.find(node) == internal_valTest_vars.end()
&& internal_unrollTest_vars.find(node) == internal_unrollTest_vars.end()) {
if (varMap[node] != 1) {
TRACE("str", tout << "new variable: " << mk_pp(node, get_manager()) << std::endl;);
}
varMap[node] = 1;
}
// check whether the node is a function that we want to inspect
else if (is_app(node)) {
app * aNode = to_app(node);
if (u.str.is_length(aNode)) {
// Length
return;
} else if (u.str.is_concat(aNode)) {
expr * arg0 = aNode->get_arg(0);
expr * arg1 = aNode->get_arg(1);
bool arg0HasEq = false;
bool arg1HasEq = false;
expr * arg0Val = get_eqc_value(arg0, arg0HasEq);
expr * arg1Val = get_eqc_value(arg1, arg1HasEq);
int canskip = 0;
zstring tmp;
u.str.is_string(arg0Val, tmp);
if (arg0HasEq && tmp.empty()) {
canskip = 1;
}
u.str.is_string(arg1Val, tmp);
if (canskip == 0 && arg1HasEq && tmp.empty()) {
canskip = 1;
}
if (canskip == 0 && concatMap.find(node) == concatMap.end()) {
concatMap[node] = 1;
}
} else if (u.re.is_unroll(aNode)) {
// Unroll
if (unrollMap.find(node) == unrollMap.end()) {
unrollMap[node] = 1;
}
}
// recursively visit all arguments
for (unsigned i = 0; i < aNode->get_num_args(); ++i) {
expr * arg = aNode->get_arg(i);
classify_ast_by_type(arg, varMap, concatMap, unrollMap);
}
}
}
// NOTE: this function used to take an argument `Z3_ast node`;
// it was not used and so was removed from the signature
void theory_str::classify_ast_by_type_in_positive_context(std::map<expr*, int> & varMap,
std::map<expr*, int> & concatMap, std::map<expr*, int> & unrollMap) {
context & ctx = get_context();
ast_manager & m = get_manager();
expr_ref_vector assignments(m);
ctx.get_assignments(assignments);
for (expr_ref_vector::iterator it = assignments.begin(); it != assignments.end(); ++it) {
expr * argAst = *it;
// the original code jumped through some hoops to check whether the AST node
// is a function, then checked whether that function is "interesting".
// however, the only thing that's considered "interesting" is an equality predicate.
// so we bypass a huge amount of work by doing the following...
if (m.is_eq(argAst)) {
TRACE("str", tout
<< "eq ast " << mk_pp(argAst, m) << " is between args of sort "
<< m.get_sort(to_app(argAst)->get_arg(0))->get_name()
<< std::endl;);
classify_ast_by_type(argAst, varMap, concatMap, unrollMap);
}
}
}
inline expr * theory_str::get_alias_index_ast(std::map<expr*, expr*> & aliasIndexMap, expr * node) {
if (aliasIndexMap.find(node) != aliasIndexMap.end())
return aliasIndexMap[node];
else
return node;
}
inline expr * theory_str::getMostLeftNodeInConcat(expr * node) {
app * aNode = to_app(node);
if (!u.str.is_concat(aNode)) {
return node;
} else {
expr * concatArgL = aNode->get_arg(0);
return getMostLeftNodeInConcat(concatArgL);
}
}
inline expr * theory_str::getMostRightNodeInConcat(expr * node) {
app * aNode = to_app(node);
if (!u.str.is_concat(aNode)) {
return node;
} else {
expr * concatArgR = aNode->get_arg(1);
return getMostRightNodeInConcat(concatArgR);
}
}
void theory_str::trace_ctx_dep(std::ofstream & tout,
std::map<expr*, expr*> & aliasIndexMap,
std::map<expr*, expr*> & var_eq_constStr_map,
std::map<expr*, std::map<expr*, int> > & var_eq_concat_map,
std::map<expr*, std::map<expr*, int> > & var_eq_unroll_map,
std::map<expr*, expr*> & concat_eq_constStr_map,
std::map<expr*, std::map<expr*, int> > & concat_eq_concat_map,
std::map<expr*, std::set<expr*> > & unrollGroupMap) {
#ifdef _TRACE
context & ctx = get_context();
ast_manager & mgr = get_manager();
{
tout << "(0) alias: variables" << std::endl;
std::map<expr*, std::map<expr*, int> > aliasSumMap;
std::map<expr*, expr*>::iterator itor0 = aliasIndexMap.begin();
for (; itor0 != aliasIndexMap.end(); itor0++) {
aliasSumMap[itor0->second][itor0->first] = 1;
}
std::map<expr*, std::map<expr*, int> >::iterator keyItor = aliasSumMap.begin();
for (; keyItor != aliasSumMap.end(); keyItor++) {
tout << " * ";
tout << mk_pp(keyItor->first, mgr);
tout << " : ";
std::map<expr*, int>::iterator innerItor = keyItor->second.begin();
for (; innerItor != keyItor->second.end(); innerItor++) {
tout << mk_pp(innerItor->first, mgr);
tout << ", ";
}
tout << std::endl;
}
tout << std::endl;
}
{
tout << "(1) var = constStr:" << std::endl;
std::map<expr*, expr*>::iterator itor1 = var_eq_constStr_map.begin();
for (; itor1 != var_eq_constStr_map.end(); itor1++) {
tout << " * ";
tout << mk_pp(itor1->first, mgr);
tout << " = ";
tout << mk_pp(itor1->second, mgr);
if (!in_same_eqc(itor1->first, itor1->second)) {
tout << " (not true in ctx)";
}
tout << std::endl;
}
tout << std::endl;
}
{
tout << "(2) var = concat:" << std::endl;
std::map<expr*, std::map<expr*, int> >::iterator itor2 = var_eq_concat_map.begin();
for (; itor2 != var_eq_concat_map.end(); itor2++) {
tout << " * ";
tout << mk_pp(itor2->first, mgr);
tout << " = { ";
std::map<expr*, int>::iterator i_itor = itor2->second.begin();
for (; i_itor != itor2->second.end(); i_itor++) {
tout << mk_pp(i_itor->first, mgr);
tout << ", ";
}
tout << std::endl;
}
tout << std::endl;
}
{
tout << "(3) var = unrollFunc:" << std::endl;
std::map<expr*, std::map<expr*, int> >::iterator itor2 = var_eq_unroll_map.begin();
for (; itor2 != var_eq_unroll_map.end(); itor2++) {
tout << " * " << mk_pp(itor2->first, mgr) << " = { ";
std::map<expr*, int>::iterator i_itor = itor2->second.begin();
for (; i_itor != itor2->second.end(); i_itor++) {
tout << mk_pp(i_itor->first, mgr) << ", ";
}
tout << " }" << std::endl;
}
tout << std::endl;
}
{
tout << "(4) concat = constStr:" << std::endl;
std::map<expr*, expr*>::iterator itor3 = concat_eq_constStr_map.begin();
for (; itor3 != concat_eq_constStr_map.end(); itor3++) {
tout << " * ";
tout << mk_pp(itor3->first, mgr);
tout << " = ";
tout << mk_pp(itor3->second, mgr);
tout << std::endl;
}
tout << std::endl;
}
{
tout << "(5) eq concats:" << std::endl;
std::map<expr*, std::map<expr*, int> >::iterator itor4 = concat_eq_concat_map.begin();
for (; itor4 != concat_eq_concat_map.end(); itor4++) {
if (itor4->second.size() > 1) {
std::map<expr*, int>::iterator i_itor = itor4->second.begin();
tout << " * ";
for (; i_itor != itor4->second.end(); i_itor++) {
tout << mk_pp(i_itor->first, mgr);
tout << " , ";
}
tout << std::endl;
}
}
tout << std::endl;
}
{
tout << "(6) eq unrolls:" << std::endl;
std::map<expr*, std::set<expr*> >::iterator itor5 = unrollGroupMap.begin();
for (; itor5 != unrollGroupMap.end(); itor5++) {
tout << " * ";
std::set<expr*>::iterator i_itor = itor5->second.begin();
for (; i_itor != itor5->second.end(); i_itor++) {
tout << mk_pp(*i_itor, mgr) << ", ";
}
tout << std::endl;
}
tout << std::endl;
}
{
tout << "(7) unroll = concats:" << std::endl;
std::map<expr*, std::set<expr*> >::iterator itor5 = unrollGroupMap.begin();
for (; itor5 != unrollGroupMap.end(); itor5++) {
tout << " * ";
expr * unroll = itor5->first;
tout << mk_pp(unroll, mgr) << std::endl;
enode * e_curr = ctx.get_enode(unroll);
enode * e_curr_end = e_curr;
do {
app * curr = e_curr->get_owner();
if (u.str.is_concat(curr)) {
tout << " >>> " << mk_pp(curr, mgr) << std::endl;
}
e_curr = e_curr->get_next();
} while (e_curr != e_curr_end);
tout << std::endl;
}
tout << std::endl;
}
#else
return;
#endif // _TRACE
}
/*
* Dependence analysis from current context assignment
* - "freeVarMap" contains a set of variables that doesn't constrained by Concats.
* But it's possible that it's bounded by unrolls
* For the case of
* (1) var1 = unroll(r1, t1)
* var1 is in the freeVarMap
* > should unroll r1 for var1
* (2) var1 = unroll(r1, t1) /\ var1 = Concat(var2, var3)
* var2, var3 are all in freeVar
* > should split the unroll function so that var2 and var3 are bounded by new unrolls
*/
int theory_str::ctx_dep_analysis(std::map<expr*, int> & strVarMap, std::map<expr*, int> & freeVarMap,
std::map<expr*, std::set<expr*> > & unrollGroupMap, std::map<expr*, std::map<expr*, int> > & var_eq_concat_map) {
std::map<expr*, int> concatMap;
std::map<expr*, int> unrollMap;
std::map<expr*, expr*> aliasIndexMap;
std::map<expr*, expr*> var_eq_constStr_map;
std::map<expr*, expr*> concat_eq_constStr_map;
std::map<expr*, std::map<expr*, int> > var_eq_unroll_map;
std::map<expr*, std::map<expr*, int> > concat_eq_concat_map;
std::map<expr*, std::map<expr*, int> > depMap;
context & ctx = get_context();
ast_manager & m = get_manager();
// note that the old API concatenated these assignments into
// a massive conjunction; we may have the opportunity to avoid that here
expr_ref_vector assignments(m);
ctx.get_assignments(assignments);
// Step 1: get variables / concat AST appearing in the context
// the thing we iterate over should just be variable_set - internal_variable_set
// so we avoid computing the set difference (but this might be slower)
for(obj_hashtable<expr>::iterator it = variable_set.begin(); it != variable_set.end(); ++it) {
expr* var = *it;
if (internal_variable_set.find(var) == internal_variable_set.end()) {
TRACE("str", tout << "new variable: " << mk_pp(var, m) << std::endl;);
strVarMap[*it] = 1;
}
}
classify_ast_by_type_in_positive_context(strVarMap, concatMap, unrollMap);
std::map<expr*, expr*> aliasUnrollSet;
std::map<expr*, int>::iterator unrollItor = unrollMap.begin();
for (; unrollItor != unrollMap.end(); ++unrollItor) {
if (aliasUnrollSet.find(unrollItor->first) != aliasUnrollSet.end()) {
continue;
}
expr * aRoot = NULL;
enode * e_currEqc = ctx.get_enode(unrollItor->first);
enode * e_curr = e_currEqc;
do {
app * curr = e_currEqc->get_owner();
if (u.re.is_unroll(curr)) {
if (aRoot == NULL) {
aRoot = curr;
}
aliasUnrollSet[curr] = aRoot;
}
e_currEqc = e_currEqc->get_next();
} while (e_currEqc != e_curr);
}
for (unrollItor = unrollMap.begin(); unrollItor != unrollMap.end(); unrollItor++) {
expr * unrFunc = unrollItor->first;
expr * urKey = aliasUnrollSet[unrFunc];
unrollGroupMap[urKey].insert(unrFunc);
}
// Step 2: collect alias relation
// e.g. suppose we have the equivalence class {x, y, z};
// then we set aliasIndexMap[y] = x
// and aliasIndexMap[z] = x
std::map<expr*, int>::iterator varItor = strVarMap.begin();
for (; varItor != strVarMap.end(); ++varItor) {
if (aliasIndexMap.find(varItor->first) != aliasIndexMap.end()) {
continue;
}
expr * aRoot = NULL;
expr * curr = varItor->first;
do {
if (variable_set.find(curr) != variable_set.end()) {
if (aRoot == NULL) {
aRoot = curr;
} else {
aliasIndexMap[curr] = aRoot;
}
}
curr = get_eqc_next(curr);
} while (curr != varItor->first);
}
// Step 3: Collect interested cases
varItor = strVarMap.begin();
for (; varItor != strVarMap.end(); ++varItor) {
expr * deAliasNode = get_alias_index_ast(aliasIndexMap, varItor->first);
// Case 1: variable = string constant
// e.g. z = "str1" ::= var_eq_constStr_map[z] = "str1"
if (var_eq_constStr_map.find(deAliasNode) == var_eq_constStr_map.end()) {
bool nodeHasEqcValue = false;
expr * nodeValue = get_eqc_value(deAliasNode, nodeHasEqcValue);
if (nodeHasEqcValue) {
var_eq_constStr_map[deAliasNode] = nodeValue;
}
}
// Case 2: var_eq_concat
// e.g. z = concat("str1", b) ::= var_eq_concat[z][concat(c, "str2")] = 1
// var_eq_unroll
// e.g. z = unroll(...) ::= var_eq_unroll[z][unroll(...)] = 1
if (var_eq_concat_map.find(deAliasNode) == var_eq_concat_map.end()) {
expr * curr = get_eqc_next(deAliasNode);
while (curr != deAliasNode) {
app * aCurr = to_app(curr);
// collect concat
if (u.str.is_concat(aCurr)) {
expr * arg0 = aCurr->get_arg(0);
expr * arg1 = aCurr->get_arg(1);
bool arg0HasEqcValue = false;
bool arg1HasEqcValue = false;
expr * arg0_value = get_eqc_value(arg0, arg0HasEqcValue);
expr * arg1_value = get_eqc_value(arg1, arg1HasEqcValue);
bool is_arg0_emptyStr = false;
if (arg0HasEqcValue) {
zstring strval;
u.str.is_string(arg0_value, strval);
if (strval.empty()) {
is_arg0_emptyStr = true;
}
}
bool is_arg1_emptyStr = false;
if (arg1HasEqcValue) {
zstring strval;
u.str.is_string(arg1_value, strval);
if (strval.empty()) {
is_arg1_emptyStr = true;
}
}
if (!is_arg0_emptyStr && !is_arg1_emptyStr) {
var_eq_concat_map[deAliasNode][curr] = 1;
}
} else if (u.re.is_unroll(to_app(curr))) {
var_eq_unroll_map[deAliasNode][curr] = 1;
}
curr = get_eqc_next(curr);
}
}
} // for(varItor in strVarMap)
// --------------------------------------------------
// * collect aliasing relation among eq concats
// e.g EQC={concat1, concat2, concat3}
// concats_eq_Index_map[concat2] = concat1
// concats_eq_Index_map[concat3] = concat1
// --------------------------------------------------
std::map<expr*, expr*> concats_eq_index_map;
std::map<expr*, int>::iterator concatItor = concatMap.begin();
for(; concatItor != concatMap.end(); ++concatItor) {
if (concats_eq_index_map.find(concatItor->first) != concats_eq_index_map.end()) {
continue;
}
expr * aRoot = NULL;
expr * curr = concatItor->first;
do {
if (u.str.is_concat(to_app(curr))) {
if (aRoot == NULL) {
aRoot = curr;
} else {
concats_eq_index_map[curr] = aRoot;
}
}
curr = get_eqc_next(curr);
} while (curr != concatItor->first);
}
concatItor = concatMap.begin();
for(; concatItor != concatMap.end(); ++concatItor) {
expr * deAliasConcat = NULL;
if (concats_eq_index_map.find(concatItor->first) != concats_eq_index_map.end()) {
deAliasConcat = concats_eq_index_map[concatItor->first];
} else {
deAliasConcat = concatItor->first;
}
// (3) concat_eq_conststr, e.g. concat(a,b) = "str1"
if (concat_eq_constStr_map.find(deAliasConcat) == concat_eq_constStr_map.end()) {
bool nodeHasEqcValue = false;
expr * nodeValue = get_eqc_value(deAliasConcat, nodeHasEqcValue);
if (nodeHasEqcValue) {
concat_eq_constStr_map[deAliasConcat] = nodeValue;
}
}
// (4) concat_eq_concat, e.g.
// concat(a,b) = concat("str1", c) AND z = concat(a,b) AND z = concat(e,f)
if (concat_eq_concat_map.find(deAliasConcat) == concat_eq_concat_map.end()) {
expr * curr = deAliasConcat;
do {
if (u.str.is_concat(to_app(curr))) {
// curr cannot be reduced
if (concatMap.find(curr) != concatMap.end()) {
concat_eq_concat_map[deAliasConcat][curr] = 1;
}
}
curr = get_eqc_next(curr);
} while (curr != deAliasConcat);
}
}
// print some debugging info
TRACE("str", trace_ctx_dep(tout, aliasIndexMap, var_eq_constStr_map,
var_eq_concat_map, var_eq_unroll_map,
concat_eq_constStr_map, concat_eq_concat_map, unrollGroupMap););
if (!contain_pair_bool_map.empty()) {
compute_contains(aliasIndexMap, concats_eq_index_map, var_eq_constStr_map, concat_eq_constStr_map, var_eq_concat_map);
}
// step 4: dependence analysis
// (1) var = string constant
for (std::map<expr*, expr*>::iterator itor = var_eq_constStr_map.begin();
itor != var_eq_constStr_map.end(); ++itor) {
expr * var = get_alias_index_ast(aliasIndexMap, itor->first);
expr * strAst = itor->second;
depMap[var][strAst] = 1;
}
// (2) var = concat
for (std::map<expr*, std::map<expr*, int> >::iterator itor = var_eq_concat_map.begin();
itor != var_eq_concat_map.end(); ++itor) {
expr * var = get_alias_index_ast(aliasIndexMap, itor->first);
for (std::map<expr*, int>::iterator itor1 = itor->second.begin(); itor1 != itor->second.end(); ++itor1) {
expr * concat = itor1->first;
std::map<expr*, int> inVarMap;
std::map<expr*, int> inConcatMap;
std::map<expr*, int> inUnrollMap;
classify_ast_by_type(concat, inVarMap, inConcatMap, inUnrollMap);
for (std::map<expr*, int>::iterator itor2 = inVarMap.begin(); itor2 != inVarMap.end(); ++itor2) {
expr * varInConcat = get_alias_index_ast(aliasIndexMap, itor2->first);
if (!(depMap[var].find(varInConcat) != depMap[var].end() && depMap[var][varInConcat] == 1)) {
depMap[var][varInConcat] = 2;
}
}
}
}
for (std::map<expr*, std::map<expr*, int> >::iterator itor = var_eq_unroll_map.begin();
itor != var_eq_unroll_map.end(); itor++) {
expr * var = get_alias_index_ast(aliasIndexMap, itor->first);
for (std::map<expr*, int>::iterator itor1 = itor->second.begin(); itor1 != itor->second.end(); itor1++) {
expr * unrollFunc = itor1->first;
std::map<expr*, int> inVarMap;
std::map<expr*, int> inConcatMap;
std::map<expr*, int> inUnrollMap;
classify_ast_by_type(unrollFunc, inVarMap, inConcatMap, inUnrollMap);
for (std::map<expr*, int>::iterator itor2 = inVarMap.begin(); itor2 != inVarMap.end(); itor2++) {
expr * varInFunc = get_alias_index_ast(aliasIndexMap, itor2->first);
TRACE("str", tout << "var in unroll = " <<
mk_ismt2_pp(itor2->first, m) << std::endl
<< "dealiased var = " << mk_ismt2_pp(varInFunc, m) << std::endl;);
// it's possible that we have both (Unroll $$_regVar_0 $$_unr_0) /\ (Unroll abcd $$_unr_0),
// while $$_regVar_0 = "abcd"
// have to exclude such cases
bool varHasValue = false;
get_eqc_value(varInFunc, varHasValue);
if (varHasValue)
continue;
if (depMap[var].find(varInFunc) == depMap[var].end()) {
depMap[var][varInFunc] = 6;
}
}
}
}
// (3) concat = string constant
for (std::map<expr*, expr*>::iterator itor = concat_eq_constStr_map.begin();
itor != concat_eq_constStr_map.end(); itor++) {
expr * concatAst = itor->first;
expr * constStr = itor->second;
std::map<expr*, int> inVarMap;
std::map<expr*, int> inConcatMap;
std::map<expr*, int> inUnrollMap;
classify_ast_by_type(concatAst, inVarMap, inConcatMap, inUnrollMap);
for (std::map<expr*, int>::iterator itor2 = inVarMap.begin(); itor2 != inVarMap.end(); itor2++) {
expr * varInConcat = get_alias_index_ast(aliasIndexMap, itor2->first);
if (!(depMap[varInConcat].find(constStr) != depMap[varInConcat].end() && depMap[varInConcat][constStr] == 1))
depMap[varInConcat][constStr] = 3;
}
}
// (4) equivalent concats
// - possibility 1 : concat("str", v1) = concat(concat(v2, v3), v4) = concat(v5, v6)
// ==> v2, v5 are constrained by "str"
// - possibility 2 : concat(v1, "str") = concat(v2, v3) = concat(v4, v5)
// ==> v2, v4 are constrained by "str"
//--------------------------------------------------------------
std::map<expr*, expr*> mostLeftNodes;
std::map<expr*, expr*> mostRightNodes;
std::map<expr*, int> mLIdxMap;
std::map<int, std::set<expr*> > mLMap;
std::map<expr*, int> mRIdxMap;
std::map<int, std::set<expr*> > mRMap;
std::set<expr*> nSet;
for (std::map<expr*, std::map<expr*, int> >::iterator itor = concat_eq_concat_map.begin();
itor != concat_eq_concat_map.end(); itor++) {
mostLeftNodes.clear();
mostRightNodes.clear();
expr * mLConst = NULL;
expr * mRConst = NULL;
for (std::map<expr*, int>::iterator itor1 = itor->second.begin(); itor1 != itor->second.end(); itor1++) {
expr * concatNode = itor1->first;
expr * mLNode = getMostLeftNodeInConcat(concatNode);
zstring strval;
if (u.str.is_string(to_app(mLNode), strval)) {
if (mLConst == NULL && strval.empty()) {
mLConst = mLNode;
}
} else {
mostLeftNodes[mLNode] = concatNode;
}
expr * mRNode = getMostRightNodeInConcat(concatNode);
if (u.str.is_string(to_app(mRNode), strval)) {
if (mRConst == NULL && strval.empty()) {
mRConst = mRNode;
}
} else {
mostRightNodes[mRNode] = concatNode;
}
}
if (mLConst != NULL) {
// -------------------------------------------------------------------------------------
// The left most variable in a concat is constrained by a constant string in eqc concat
// -------------------------------------------------------------------------------------
// e.g. Concat(x, ...) = Concat("abc", ...)
// -------------------------------------------------------------------------------------
for (std::map<expr*, expr*>::iterator itor1 = mostLeftNodes.begin();
itor1 != mostLeftNodes.end(); itor1++) {
expr * deVar = get_alias_index_ast(aliasIndexMap, itor1->first);
if (depMap[deVar].find(mLConst) == depMap[deVar].end() || depMap[deVar][mLConst] != 1) {
depMap[deVar][mLConst] = 4;
}
}
}
{
// -------------------------------------------------------------------------------------
// The left most variables in eqc concats are constrained by each other
// -------------------------------------------------------------------------------------
// e.g. concat(x, ...) = concat(u, ...) = ...
// x and u are constrained by each other
// -------------------------------------------------------------------------------------
nSet.clear();
std::map<expr*, expr*>::iterator itl = mostLeftNodes.begin();
for (; itl != mostLeftNodes.end(); itl++) {
bool lfHasEqcValue = false;
get_eqc_value(itl->first, lfHasEqcValue);
if (lfHasEqcValue)
continue;
expr * deVar = get_alias_index_ast(aliasIndexMap, itl->first);
nSet.insert(deVar);
}
if (nSet.size() > 1) {
int lId = -1;
for (std::set<expr*>::iterator itor2 = nSet.begin(); itor2 != nSet.end(); itor2++) {
if (mLIdxMap.find(*itor2) != mLIdxMap.end()) {
lId = mLIdxMap[*itor2];
break;
}
}
if (lId == -1)
lId = mLMap.size();
for (std::set<expr*>::iterator itor2 = nSet.begin(); itor2 != nSet.end(); itor2++) {
bool itorHasEqcValue = false;
get_eqc_value(*itor2, itorHasEqcValue);
if (itorHasEqcValue)
continue;
mLIdxMap[*itor2] = lId;
mLMap[lId].insert(*itor2);
}
}
}
if (mRConst != NULL) {
for (std::map<expr*, expr*>::iterator itor1 = mostRightNodes.begin();
itor1 != mostRightNodes.end(); itor1++) {
expr * deVar = get_alias_index_ast(aliasIndexMap, itor1->first);
if (depMap[deVar].find(mRConst) == depMap[deVar].end() || depMap[deVar][mRConst] != 1) {
depMap[deVar][mRConst] = 5;
}
}
}
{
nSet.clear();
std::map<expr*, expr*>::iterator itr = mostRightNodes.begin();
for (; itr != mostRightNodes.end(); itr++) {
expr * deVar = get_alias_index_ast(aliasIndexMap, itr->first);
nSet.insert(deVar);
}
if (nSet.size() > 1) {
int rId = -1;
std::set<expr*>::iterator itor2 = nSet.begin();
for (; itor2 != nSet.end(); itor2++) {
if (mRIdxMap.find(*itor2) != mRIdxMap.end()) {
rId = mRIdxMap[*itor2];
break;
}
}
if (rId == -1)
rId = mRMap.size();
for (itor2 = nSet.begin(); itor2 != nSet.end(); itor2++) {
bool rHasEqcValue = false;
get_eqc_value(*itor2, rHasEqcValue);
if (rHasEqcValue)
continue;
mRIdxMap[*itor2] = rId;
mRMap[rId].insert(*itor2);
}
}
}
}
// print the dependence map
TRACE("str",
tout << "Dependence Map" << std::endl;
for(std::map<expr*, std::map<expr*, int> >::iterator itor = depMap.begin(); itor != depMap.end(); itor++) {
tout << mk_pp(itor->first, m);
rational nnLen;
bool nnLen_exists = get_len_value(itor->first, nnLen);
tout << " [len = " << (nnLen_exists ? nnLen.to_string() : "?") << "] \t-->\t";
for (std::map<expr*, int>::iterator itor1 = itor->second.begin(); itor1 != itor->second.end(); itor1++) {
tout << mk_pp(itor1->first, m) << "(" << itor1->second << "), ";
}
tout << std::endl;
}
);
// step, errr, 5: compute free variables based on the dependence map
// the case dependence map is empty, every var in VarMap is free
//---------------------------------------------------------------
// remove L/R most var in eq concat since they are constrained with each other
std::map<expr*, std::map<expr*, int> > lrConstrainedMap;
for (std::map<int, std::set<expr*> >::iterator itor = mLMap.begin(); itor != mLMap.end(); itor++) {
for (std::set<expr*>::iterator it1 = itor->second.begin(); it1 != itor->second.end(); it1++) {
std::set<expr*>::iterator it2 = it1;
it2++;
for (; it2 != itor->second.end(); it2++) {
expr * n1 = *it1;
expr * n2 = *it2;
lrConstrainedMap[n1][n2] = 1;
lrConstrainedMap[n2][n1] = 1;
}
}
}
for (std::map<int, std::set<expr*> >::iterator itor = mRMap.begin(); itor != mRMap.end(); itor++) {
for (std::set<expr*>::iterator it1 = itor->second.begin(); it1 != itor->second.end(); it1++) {
std::set<expr*>::iterator it2 = it1;
it2++;
for (; it2 != itor->second.end(); it2++) {
expr * n1 = *it1;
expr * n2 = *it2;
lrConstrainedMap[n1][n2] = 1;
lrConstrainedMap[n2][n1] = 1;
}
}
}
if (depMap.size() == 0) {
std::map<expr*, int>::iterator itor = strVarMap.begin();
for (; itor != strVarMap.end(); itor++) {
expr * var = get_alias_index_ast(aliasIndexMap, itor->first);
if (lrConstrainedMap.find(var) == lrConstrainedMap.end()) {
freeVarMap[var] = 1;
} else {
int lrConstainted = 0;
std::map<expr*, int>::iterator lrit = freeVarMap.begin();
for (; lrit != freeVarMap.end(); lrit++) {
if (lrConstrainedMap[var].find(lrit->first) != lrConstrainedMap[var].end()) {
lrConstainted = 1;
break;
}
}
if (lrConstainted == 0) {
freeVarMap[var] = 1;
}
}
}
} else {
// if the keys in aliasIndexMap are not contained in keys in depMap, they are free
// e.g., x= y /\ x = z /\ t = "abc"
// aliasIndexMap[y]= x, aliasIndexMap[z] = x
// depMap t ~ "abc"(1)
// x should be free
std::map<expr*, int>::iterator itor2 = strVarMap.begin();
for (; itor2 != strVarMap.end(); itor2++) {
if (aliasIndexMap.find(itor2->first) != aliasIndexMap.end()) {
expr * var = aliasIndexMap[itor2->first];
if (depMap.find(var) == depMap.end()) {
if (lrConstrainedMap.find(var) == lrConstrainedMap.end()) {
freeVarMap[var] = 1;
} else {
int lrConstainted = 0;
std::map<expr*, int>::iterator lrit = freeVarMap.begin();
for (; lrit != freeVarMap.end(); lrit++) {
if (lrConstrainedMap[var].find(lrit->first) != lrConstrainedMap[var].end()) {
lrConstainted = 1;
break;
}
}
if (lrConstainted == 0) {
freeVarMap[var] = 1;
}
}
}
} else if (aliasIndexMap.find(itor2->first) == aliasIndexMap.end()) {
// if a variable is not in aliasIndexMap and not in depMap, it's free
if (depMap.find(itor2->first) == depMap.end()) {
expr * var = itor2->first;
if (lrConstrainedMap.find(var) == lrConstrainedMap.end()) {
freeVarMap[var] = 1;
} else {
int lrConstainted = 0;
std::map<expr*, int>::iterator lrit = freeVarMap.begin();
for (; lrit != freeVarMap.end(); lrit++) {
if (lrConstrainedMap[var].find(lrit->first) != lrConstrainedMap[var].end()) {
lrConstainted = 1;
break;
}
}
if (lrConstainted == 0) {
freeVarMap[var] = 1;
}
}
}
}
}
std::map<expr*, std::map<expr*, int> >::iterator itor = depMap.begin();
for (; itor != depMap.end(); itor++) {
for (std::map<expr*, int>::iterator itor1 = itor->second.begin(); itor1 != itor->second.end(); itor1++) {
if (variable_set.find(itor1->first) != variable_set.end()) { // expr type = var
expr * var = get_alias_index_ast(aliasIndexMap, itor1->first);
// if a var is dep on itself and all dependence are type 2, it's a free variable
// e.g {y --> x(2), y(2), m --> m(2), n(2)} y,m are free
{
if (depMap.find(var) == depMap.end()) {
if (freeVarMap.find(var) == freeVarMap.end()) {
if (lrConstrainedMap.find(var) == lrConstrainedMap.end()) {
freeVarMap[var] = 1;
} else {
int lrConstainted = 0;
std::map<expr*, int>::iterator lrit = freeVarMap.begin();
for (; lrit != freeVarMap.end(); lrit++) {
if (lrConstrainedMap[var].find(lrit->first) != lrConstrainedMap[var].end()) {
lrConstainted = 1;
break;
}
}
if (lrConstainted == 0) {
freeVarMap[var] = 1;
}
}
} else {
freeVarMap[var] = freeVarMap[var] + 1;
}
}
}
}
}
}
}
return 0;
}
// Check agreement between integer and string theories for the term a = (str.to-int S).
// Returns true if axioms were added, and false otherwise.
bool theory_str::finalcheck_str2int(app * a) {
bool axiomAdd = false;
context & ctx = get_context();
ast_manager & m = get_manager();
expr * S = a->get_arg(0);
// check integer theory
rational Ival;
bool Ival_exists = get_value(a, Ival);
if (Ival_exists) {
TRACE("str", tout << "integer theory assigns " << mk_pp(a, m) << " = " << Ival.to_string() << std::endl;);
// if that value is not -1, we can assert (str.to-int S) = Ival --> S = "Ival"
if (!Ival.is_minus_one()) {
zstring Ival_str(Ival.to_string().c_str());
expr_ref premise(ctx.mk_eq_atom(a, m_autil.mk_numeral(Ival, true)), m);
expr_ref conclusion(ctx.mk_eq_atom(S, mk_string(Ival_str)), m);
expr_ref axiom(rewrite_implication(premise, conclusion), m);
if (!string_int_axioms.contains(axiom)) {
string_int_axioms.insert(axiom);
assert_axiom(axiom);
m_trail_stack.push(insert_obj_trail<theory_str, expr>(string_int_axioms, axiom));
axiomAdd = true;
}
}
} else {
TRACE("str", tout << "integer theory has no assignment for " << mk_pp(a, m) << std::endl;);
NOT_IMPLEMENTED_YET();
}
return axiomAdd;
}
bool theory_str::finalcheck_int2str(app * a) {
bool axiomAdd = false;
context & ctx = get_context();
ast_manager & m = get_manager();
expr * N = a->get_arg(0);
// check string theory
bool Sval_expr_exists;
expr * Sval_expr = get_eqc_value(a, Sval_expr_exists);
if (Sval_expr_exists) {
zstring Sval;
u.str.is_string(Sval_expr, Sval);
TRACE("str", tout << "string theory assigns \"" << mk_pp(a, m) << " = " << Sval << "\n";);
// empty string --> integer value < 0
if (Sval.empty()) {
// ignore this. we should already assert the axiom for what happens when the string is ""
} else {
// nonempty string --> convert to correct integer value, or disallow it
rational convertedRepresentation(0);
rational ten(10);
bool conversionOK = true;
for (unsigned i = 0; i < Sval.length(); ++i) {
char digit = (int)Sval[i];
if (isdigit((int)digit)) {
std::string sDigit(1, digit);
int val = atoi(sDigit.c_str());
convertedRepresentation = (ten * convertedRepresentation) + rational(val);
} else {
// not a digit, invalid
TRACE("str", tout << "str.to-int argument contains non-digit character '" << digit << "'" << std::endl;);
conversionOK = false;
break;
}
}
if (conversionOK) {
expr_ref premise(ctx.mk_eq_atom(a, mk_string(Sval)), m);
expr_ref conclusion(ctx.mk_eq_atom(N, m_autil.mk_numeral(convertedRepresentation, true)), m);
expr_ref axiom(rewrite_implication(premise, conclusion), m);
if (!string_int_axioms.contains(axiom)) {
string_int_axioms.insert(axiom);
assert_axiom(axiom);
m_trail_stack.push(insert_obj_trail<theory_str, expr>(string_int_axioms, axiom));
axiomAdd = true;
}
} else {
expr_ref axiom(m.mk_not(ctx.mk_eq_atom(a, mk_string(Sval))), m);
// always assert this axiom because this is a conflict clause
assert_axiom(axiom);
axiomAdd = true;
}
}
} else {
TRACE("str", tout << "string theory has no assignment for " << mk_pp(a, m) << std::endl;);
NOT_IMPLEMENTED_YET();
}
return axiomAdd;
}
void theory_str::collect_var_concat(expr * node, std::set<expr*> & varSet, std::set<expr*> & concatSet) {
if (variable_set.find(node) != variable_set.end()) {
if (internal_lenTest_vars.find(node) == internal_lenTest_vars.end()) {
varSet.insert(node);
}
}
else if (is_app(node)) {
app * aNode = to_app(node);
if (u.str.is_length(aNode)) {
// Length
return;
}
if (u.str.is_concat(aNode)) {
if (concatSet.find(node) == concatSet.end()) {
concatSet.insert(node);
}
}
// recursively visit all arguments
for (unsigned i = 0; i < aNode->get_num_args(); ++i) {
expr * arg = aNode->get_arg(i);
collect_var_concat(arg, varSet, concatSet);
}
}
}
bool theory_str::propagate_length_within_eqc(expr * var) {
bool res = false;
ast_manager & m = get_manager();
context & ctx = get_context();
TRACE("str", tout << "propagate_length_within_eqc: " << mk_ismt2_pp(var, m) << std::endl ;);
rational varLen;
if (! get_len_value(var, varLen)) {
bool hasLen = false;
expr * nodeWithLen= var;
do {
if (get_len_value(nodeWithLen, varLen)) {
hasLen = true;
break;
}
nodeWithLen = get_eqc_next(nodeWithLen);
} while (nodeWithLen != var);
if (hasLen) {
// var = nodeWithLen --> |var| = |nodeWithLen|
expr_ref_vector l_items(m);
expr_ref varEqNode(ctx.mk_eq_atom(var, nodeWithLen), m);
l_items.push_back(varEqNode);
expr_ref nodeWithLenExpr (mk_strlen(nodeWithLen), m);
expr_ref varLenExpr (mk_int(varLen), m);
expr_ref lenEqNum(ctx.mk_eq_atom(nodeWithLenExpr, varLenExpr), m);
l_items.push_back(lenEqNum);
expr_ref axl(m.mk_and(l_items.size(), l_items.c_ptr()), m);
expr_ref varLen(mk_strlen(var), m);
expr_ref axr(ctx.mk_eq_atom(varLen, mk_int(varLen)), m);
assert_implication(axl, axr);
TRACE("str", tout << mk_ismt2_pp(axl, m) << std::endl << " ---> " << std::endl << mk_ismt2_pp(axr, m););
res = true;
}
}
return res;
}
bool theory_str::propagate_length(std::set<expr*> & varSet, std::set<expr*> & concatSet, std::map<expr*, int> & exprLenMap) {
context & ctx = get_context();
ast_manager & m = get_manager();
expr_ref_vector assignments(m);
ctx.get_assignments(assignments);
bool axiomAdded = false;
// collect all concats in context
for (expr_ref_vector::iterator it = assignments.begin(); it != assignments.end(); ++it) {
if (! ctx.is_relevant(*it)) {
continue;
}
if (m.is_eq(*it)) {
collect_var_concat(*it, varSet, concatSet);
}
}
// iterate each concat
// if a concat doesn't have length info, check if the length of all leaf nodes can be resolved
for (std::set<expr*>::iterator it = concatSet.begin(); it != concatSet.end(); it++) {
expr * concat = *it;
rational lenValue;
expr_ref concatlenExpr (mk_strlen(concat), m) ;
bool allLeafResolved = true;
if (! get_value(concatlenExpr, lenValue)) {
// the length fo concat is unresolved yet
if (get_len_value(concat, lenValue)) {
// but all leaf nodes have length information
TRACE("str", tout << "* length pop-up: " << mk_ismt2_pp(concat, m) << "| = " << lenValue << std::endl;);
std::set<expr*> leafNodes;
get_unique_non_concat_nodes(concat, leafNodes);
expr_ref_vector l_items(m);
for (std::set<expr*>::iterator leafIt = leafNodes.begin(); leafIt != leafNodes.end(); ++leafIt) {
rational leafLenValue;
if (get_len_value(*leafIt, leafLenValue)) {
expr_ref leafItLenExpr (mk_strlen(*leafIt), m);
expr_ref leafLenValueExpr (mk_int(leafLenValue), m);
expr_ref lcExpr (ctx.mk_eq_atom(leafItLenExpr, leafLenValueExpr), m);
l_items.push_back(lcExpr);
} else {
allLeafResolved = false;
break;
}
}
if (allLeafResolved) {
expr_ref axl(m.mk_and(l_items.size(), l_items.c_ptr()), m);
expr_ref lenValueExpr (mk_int(lenValue), m);
expr_ref axr(ctx.mk_eq_atom(concatlenExpr, lenValueExpr), m);
assert_implication(axl, axr);
TRACE("str", tout << mk_ismt2_pp(axl, m) << std::endl << " ---> " << std::endl << mk_ismt2_pp(axr, m)<< std::endl;);
axiomAdded = true;
}
}
}
}
// if no concat length is propagated, check the length of variables.
if (! axiomAdded) {
for (std::set<expr*>::iterator it = varSet.begin(); it != varSet.end(); it++) {
expr * var = *it;
rational lenValue;
expr_ref varlen (mk_strlen(var), m) ;
if (! get_value(varlen, lenValue)) {
if (propagate_length_within_eqc(var)) {
axiomAdded = true;
}
}
}
}
return axiomAdded;
}
void theory_str::get_unique_non_concat_nodes(expr * node, std::set<expr*> & argSet) {
app * a_node = to_app(node);
if (!u.str.is_concat(a_node)) {
argSet.insert(node);
return;
} else {
SASSERT(a_node->get_num_args() == 2);
expr * leftArg = a_node->get_arg(0);
expr * rightArg = a_node->get_arg(1);
get_unique_non_concat_nodes(leftArg, argSet);
get_unique_non_concat_nodes(rightArg, argSet);
}
}
final_check_status theory_str::final_check_eh() {
context & ctx = get_context();
ast_manager & m = get_manager();
expr_ref_vector assignments(m);
ctx.get_assignments(assignments);
if (opt_VerifyFinalCheckProgress) {
finalCheckProgressIndicator = false;
}
TRACE("str", tout << "final check" << std::endl;);
TRACE_CODE(if (is_trace_enabled("t_str_dump_assign")) { dump_assignments(); });
check_variable_scope();
if (opt_DeferEQCConsistencyCheck) {
TRACE("str", tout << "performing deferred EQC consistency check" << std::endl;);
std::set<enode*> eqc_roots;
for (ptr_vector<enode>::const_iterator it = ctx.begin_enodes(); it != ctx.end_enodes(); ++it) {
enode * e = *it;
enode * root = e->get_root();
eqc_roots.insert(root);
}
bool found_inconsistency = false;
for (std::set<enode*>::iterator it = eqc_roots.begin(); it != eqc_roots.end(); ++it) {
enode * e = *it;
app * a = e->get_owner();
if (!(m.get_sort(a) == u.str.mk_string_sort())) {
TRACE("str", tout << "EQC root " << mk_pp(a, m) << " not a string term; skipping" << std::endl;);
} else {
TRACE("str", tout << "EQC root " << mk_pp(a, m) << " is a string term. Checking this EQC" << std::endl;);
// first call check_concat_len_in_eqc() on each member of the eqc
enode * e_it = e;
enode * e_root = e_it;
do {
bool status = check_concat_len_in_eqc(e_it->get_owner());
if (!status) {
TRACE("str", tout << "concat-len check asserted an axiom on " << mk_pp(e_it->get_owner(), m) << std::endl;);
found_inconsistency = true;
}
e_it = e_it->get_next();
} while (e_it != e_root);
// now grab any two distinct elements from the EQC and call new_eq_check() on them
enode * e1 = e;
enode * e2 = e1->get_next();
if (e1 != e2) {
TRACE("str", tout << "deferred new_eq_check() over EQC of " << mk_pp(e1->get_owner(), m) << " and " << mk_pp(e2->get_owner(), m) << std::endl;);
bool result = new_eq_check(e1->get_owner(), e2->get_owner());
if (!result) {
TRACE("str", tout << "new_eq_check found inconsistencies" << std::endl;);
found_inconsistency = true;
}
}
}
}
if (found_inconsistency) {
TRACE("str", tout << "Found inconsistency in final check! Returning to search." << std::endl;);
return FC_CONTINUE;
} else {
TRACE("str", tout << "Deferred consistency check passed. Continuing in final check." << std::endl;);
}
}
// run dependence analysis to find free string variables
std::map<expr*, int> varAppearInAssign;
std::map<expr*, int> freeVar_map;
std::map<expr*, std::set<expr*> > unrollGroup_map;
std::map<expr*, std::map<expr*, int> > var_eq_concat_map;
int conflictInDep = ctx_dep_analysis(varAppearInAssign, freeVar_map, unrollGroup_map, var_eq_concat_map);
if (conflictInDep == -1) {
// return Z3_TRUE;
return FC_DONE;
}
// enhancement: improved backpropagation of string constants into var=concat terms
bool backpropagation_occurred = false;
for (std::map<expr*, std::map<expr*, int> >::iterator veqc_map_it = var_eq_concat_map.begin();
veqc_map_it != var_eq_concat_map.end(); ++veqc_map_it) {
expr * var = veqc_map_it->first;
for (std::map<expr*, int>::iterator concat_map_it = veqc_map_it->second.begin();
concat_map_it != veqc_map_it->second.end(); ++concat_map_it) {
app * concat = to_app(concat_map_it->first);
expr * concat_lhs = concat->get_arg(0);
expr * concat_rhs = concat->get_arg(1);
// If the concat LHS and RHS both have a string constant in their EQC,
// but the var does not, then we assert an axiom of the form
// (lhs = "lhs" AND rhs = "rhs") --> (Concat lhs rhs) = "lhsrhs"
bool concat_lhs_haseqc, concat_rhs_haseqc, var_haseqc;
expr * concat_lhs_str = get_eqc_value(concat_lhs, concat_lhs_haseqc);
expr * concat_rhs_str = get_eqc_value(concat_rhs, concat_rhs_haseqc);
get_eqc_value(var, var_haseqc);
if (concat_lhs_haseqc && concat_rhs_haseqc && !var_haseqc) {
TRACE("str", tout << "backpropagate into " << mk_pp(var, m) << " = " << mk_pp(concat, m) << std::endl
<< "LHS ~= " << mk_pp(concat_lhs_str, m) << " RHS ~= " << mk_pp(concat_rhs_str, m) << std::endl;);
zstring lhsString, rhsString;
u.str.is_string(concat_lhs_str, lhsString);
u.str.is_string(concat_rhs_str, rhsString);
zstring concatString = lhsString + rhsString;
expr_ref lhs1(ctx.mk_eq_atom(concat_lhs, concat_lhs_str), m);
expr_ref lhs2(ctx.mk_eq_atom(concat_rhs, concat_rhs_str), m);
expr_ref lhs(m.mk_and(lhs1, lhs2), m);
expr_ref rhs(ctx.mk_eq_atom(concat, mk_string(concatString)), m);
assert_implication(lhs, rhs);
backpropagation_occurred = true;
}
}
}
if (backpropagation_occurred) {
TRACE("str", tout << "Resuming search due to axioms added by backpropagation." << std::endl;);
return FC_CONTINUE;
}
// enhancement: improved backpropagation of length information
{
std::set<expr*> varSet;
std::set<expr*> concatSet;
std::map<expr*, int> exprLenMap;
bool length_propagation_occurred = propagate_length(varSet, concatSet, exprLenMap);
if (length_propagation_occurred) {
TRACE("str", tout << "Resuming search due to axioms added by length propagation." << std::endl;);
return FC_CONTINUE;
}
}
bool needToAssignFreeVars = false;
std::set<expr*> free_variables;
std::set<expr*> unused_internal_variables;
{ // Z3str2 free variables check
std::map<expr*, int>::iterator itor = varAppearInAssign.begin();
for (; itor != varAppearInAssign.end(); ++itor) {
/*
std::string vName = std::string(Z3_ast_to_string(ctx, itor->first));
if (vName.length() >= 3 && vName.substr(0, 3) == "$$_")
continue;
*/
if (internal_variable_set.find(itor->first) != internal_variable_set.end()
|| regex_variable_set.find(itor->first) != regex_variable_set.end()) {
// this can be ignored, I think
TRACE("str", tout << "free internal variable " << mk_pp(itor->first, m) << " ignored" << std::endl;);
continue;
}
bool hasEqcValue = false;
expr * eqcString = get_eqc_value(itor->first, hasEqcValue);
if (!hasEqcValue) {
TRACE("str", tout << "found free variable " << mk_pp(itor->first, m) << std::endl;);
needToAssignFreeVars = true;
free_variables.insert(itor->first);
// break;
} else {
// debug
TRACE("str", tout << "variable " << mk_pp(itor->first, m) << " = " << mk_pp(eqcString, m) << std::endl;);
}
}
}
if (!needToAssignFreeVars) {
// check string-int terms
bool addedStrIntAxioms = false;
for (unsigned i = 0; i < string_int_conversion_terms.size(); ++i) {
app * ex = to_app(string_int_conversion_terms[i].get());
if (u.str.is_stoi(ex)) {
bool axiomAdd = finalcheck_str2int(ex);
if (axiomAdd) {
addedStrIntAxioms = true;
}
} else if (u.str.is_itos(ex)) {
bool axiomAdd = finalcheck_int2str(ex);
if (axiomAdd) {
addedStrIntAxioms = true;
}
} else {
UNREACHABLE();
}
}
if (addedStrIntAxioms) {
TRACE("str", tout << "Resuming search due to addition of string-integer conversion axioms." << std::endl;);
return FC_CONTINUE;
}
if (unused_internal_variables.empty()) {
TRACE("str", tout << "All variables are assigned. Done!" << std::endl;);
return FC_DONE;
} else {
TRACE("str", tout << "Assigning decoy values to free internal variables." << std::endl;);
for (std::set<expr*>::iterator it = unused_internal_variables.begin(); it != unused_internal_variables.end(); ++it) {
expr * var = *it;
expr_ref assignment(m.mk_eq(var, mk_string("**unused**")), m);
assert_axiom(assignment);
}
return FC_CONTINUE;
}
}
CTRACE("str", needToAssignFreeVars,
tout << "Need to assign values to the following free variables:" << std::endl;
for (std::set<expr*>::iterator itx = free_variables.begin(); itx != free_variables.end(); ++itx) {
tout << mk_ismt2_pp(*itx, m) << std::endl;
}
tout << "freeVar_map has the following entries:" << std::endl;
for (std::map<expr*, int>::iterator fvIt = freeVar_map.begin(); fvIt != freeVar_map.end(); fvIt++) {
expr * var = fvIt->first;
tout << mk_ismt2_pp(var, m) << std::endl;
}
);
// -----------------------------------------------------------
// variables in freeVar are those not bounded by Concats
// classify variables in freeVarMap:
// (1) freeVar = unroll(r1, t1)
// (2) vars are not bounded by either concat or unroll
// -----------------------------------------------------------
std::map<expr*, std::set<expr*> > fv_unrolls_map;
std::set<expr*> tmpSet;
expr * constValue = NULL;
for (std::map<expr*, int>::iterator fvIt2 = freeVar_map.begin(); fvIt2 != freeVar_map.end(); fvIt2++) {
expr * var = fvIt2->first;
tmpSet.clear();
get_eqc_allUnroll(var, constValue, tmpSet);
if (tmpSet.size() > 0) {
fv_unrolls_map[var] = tmpSet;
}
}
// erase var bounded by an unroll function from freeVar_map
for (std::map<expr*, std::set<expr*> >::iterator fvIt3 = fv_unrolls_map.begin();
fvIt3 != fv_unrolls_map.end(); fvIt3++) {
expr * var = fvIt3->first;
TRACE("str", tout << "erase free variable " << mk_pp(var, m) << " from freeVar_map, it is bounded by an Unroll" << std::endl;);
freeVar_map.erase(var);
}
// collect the case:
// * Concat(X, Y) = unroll(r1, t1) /\ Concat(X, Y) = unroll(r2, t2)
// concatEqUnrollsMap[Concat(X, Y)] = {unroll(r1, t1), unroll(r2, t2)}
std::map<expr*, std::set<expr*> > concatEqUnrollsMap;
for (std::map<expr*, std::set<expr*> >::iterator urItor = unrollGroup_map.begin();
urItor != unrollGroup_map.end(); urItor++) {
expr * unroll = urItor->first;
expr * curr = unroll;
do {
if (u.str.is_concat(to_app(curr))) {
concatEqUnrollsMap[curr].insert(unroll);
concatEqUnrollsMap[curr].insert(unrollGroup_map[unroll].begin(), unrollGroup_map[unroll].end());
}
enode * e_curr = ctx.get_enode(curr);
curr = e_curr->get_next()->get_owner();
// curr = get_eqc_next(curr);
} while (curr != unroll);
}
std::map<expr*, std::set<expr*> > concatFreeArgsEqUnrollsMap;
std::set<expr*> fvUnrollSet;
for (std::map<expr*, std::set<expr*> >::iterator concatItor = concatEqUnrollsMap.begin();
concatItor != concatEqUnrollsMap.end(); concatItor++) {
expr * concat = concatItor->first;
expr * concatArg1 = to_app(concat)->get_arg(0);
expr * concatArg2 = to_app(concat)->get_arg(1);
bool arg1Bounded = false;
bool arg2Bounded = false;
// arg1
if (variable_set.find(concatArg1) != variable_set.end()) {
if (freeVar_map.find(concatArg1) == freeVar_map.end()) {
arg1Bounded = true;
} else {
fvUnrollSet.insert(concatArg1);
}
} else if (u.str.is_concat(to_app(concatArg1))) {
if (concatEqUnrollsMap.find(concatArg1) == concatEqUnrollsMap.end()) {
arg1Bounded = true;
}
}
// arg2
if (variable_set.find(concatArg2) != variable_set.end()) {
if (freeVar_map.find(concatArg2) == freeVar_map.end()) {
arg2Bounded = true;
} else {
fvUnrollSet.insert(concatArg2);
}
} else if (u.str.is_concat(to_app(concatArg2))) {
if (concatEqUnrollsMap.find(concatArg2) == concatEqUnrollsMap.end()) {
arg2Bounded = true;
}
}
if (!arg1Bounded && !arg2Bounded) {
concatFreeArgsEqUnrollsMap[concat].insert(
concatEqUnrollsMap[concat].begin(),
concatEqUnrollsMap[concat].end());
}
}
for (std::set<expr*>::iterator vItor = fvUnrollSet.begin(); vItor != fvUnrollSet.end(); vItor++) {
TRACE("str", tout << "remove " << mk_pp(*vItor, m) << " from freeVar_map" << std::endl;);
freeVar_map.erase(*vItor);
}
// Assign free variables
std::set<expr*> fSimpUnroll;
constValue = NULL;
{
TRACE("str", tout << "free var map (#" << freeVar_map.size() << "):" << std::endl;
for (std::map<expr*, int>::iterator freeVarItor1 = freeVar_map.begin(); freeVarItor1 != freeVar_map.end(); freeVarItor1++) {
expr * freeVar = freeVarItor1->first;
rational lenValue;
bool lenValue_exists = get_len_value(freeVar, lenValue);
tout << mk_pp(freeVar, m) << " [depCnt = " << freeVarItor1->second << ", length = "
<< (lenValue_exists ? lenValue.to_string() : "?")
<< "]" << std::endl;
}
);
}
for (std::map<expr*, std::set<expr*> >::iterator fvIt2 = concatFreeArgsEqUnrollsMap.begin();
fvIt2 != concatFreeArgsEqUnrollsMap.end(); fvIt2++) {
expr * concat = fvIt2->first;
for (std::set<expr*>::iterator urItor = fvIt2->second.begin(); urItor != fvIt2->second.end(); urItor++) {
expr * unroll = *urItor;
process_concat_eq_unroll(concat, unroll);
}
}
// --------
// experimental free variable assignment - begin
// * special handling for variables that are not used in concat
// --------
bool testAssign = true;
if (!testAssign) {
for (std::map<expr*, int>::iterator fvIt = freeVar_map.begin(); fvIt != freeVar_map.end(); fvIt++) {
expr * freeVar = fvIt->first;
/*
std::string vName = std::string(Z3_ast_to_string(ctx, freeVar));
if (vName.length() >= 9 && vName.substr(0, 9) == "$$_regVar") {
continue;
}
*/
expr * toAssert = gen_len_val_options_for_free_var(freeVar, NULL, "");
if (toAssert != NULL) {
assert_axiom(toAssert);
}
}
} else {
process_free_var(freeVar_map);
}
// experimental free variable assignment - end
// now deal with removed free variables that are bounded by an unroll
TRACE("str", tout << "fv_unrolls_map (#" << fv_unrolls_map.size() << "):" << std::endl;);
for (std::map<expr*, std::set<expr*> >::iterator fvIt1 = fv_unrolls_map.begin();
fvIt1 != fv_unrolls_map.end(); fvIt1++) {
expr * var = fvIt1->first;
fSimpUnroll.clear();
get_eqc_simpleUnroll(var, constValue, fSimpUnroll);
if (fSimpUnroll.size() == 0) {
gen_assign_unroll_reg(fv_unrolls_map[var]);
} else {
expr * toAssert = gen_assign_unroll_Str2Reg(var, fSimpUnroll);
if (toAssert != NULL) {
assert_axiom(toAssert);
}
}
}
if (opt_VerifyFinalCheckProgress && !finalCheckProgressIndicator) {
TRACE("str", tout << "BUG: no progress in final check, giving up!!" << std::endl;);
m.raise_exception("no progress in theory_str final check");
}
return FC_CONTINUE; // since by this point we've added axioms
}
inline zstring int_to_string(int i) {
std::stringstream ss;
ss << i;
std::string str = ss.str();
return zstring(str.c_str());
}
inline std::string longlong_to_string(long long i) {
std::stringstream ss;
ss << i;
return ss.str();
}
void theory_str::print_value_tester_list(svector<std::pair<int, expr*> > & testerList) {
ast_manager & m = get_manager();
TRACE("str",
int ss = testerList.size();
tout << "valueTesterList = {";
for (int i = 0; i < ss; ++i) {
if (i % 4 == 0) {
tout << std::endl;
}
tout << "(" << testerList[i].first << ", ";
tout << mk_ismt2_pp(testerList[i].second, m);
tout << "), ";
}
tout << std::endl << "}" << std::endl;
);
}
zstring theory_str::gen_val_string(int len, int_vector & encoding) {
SASSERT(charSetSize > 0);
SASSERT(char_set != NULL);
std::string re(len, char_set[0]);
for (int i = 0; i < (int) encoding.size() - 1; i++) {
int idx = encoding[i];
re[len - 1 - i] = char_set[idx];
}
return zstring(re.c_str());
}
/*
* The return value indicates whether we covered the search space.
* - If the next encoding is valid, return false
* - Otherwise, return true
*/
bool theory_str::get_next_val_encode(int_vector & base, int_vector & next) {
SASSERT(charSetSize > 0);
TRACE("str", tout << "base vector: [ ";
for (unsigned i = 0; i < base.size(); ++i) {
tout << base[i] << " ";
}
tout << "]" << std::endl;
);
int s = 0;
int carry = 0;
next.reset();
for (int i = 0; i < (int) base.size(); i++) {
if (i == 0) {
s = base[i] + 1;
carry = s / charSetSize;
s = s % charSetSize;
next.push_back(s);
} else {
s = base[i] + carry;
carry = s / charSetSize;
s = s % charSetSize;
next.push_back(s);
}
}
if (next[next.size() - 1] > 0) {
next.reset();
return true;
} else {
return false;
}
}
expr * theory_str::gen_val_options(expr * freeVar, expr * len_indicator, expr * val_indicator,
zstring lenStr, int tries) {
ast_manager & m = get_manager();
context & ctx = get_context();
int distance = 32;
// ----------------------------------------------------------------------------------------
// generate value options encoding
// encoding is a vector of size (len + 1)
// e.g, len = 2,
// encoding {1, 2, 0} means the value option is "charSet[2]"."charSet[1]"
// the last item in the encoding indicates whether the whole space is covered
// for example, if the charSet = {a, b}. All valid encodings are
// {0, 0, 0}, {1, 0, 0}, {0, 1, 0}, {1, 1, 0}
// if add 1 to the last one, we get
// {0, 0, 1}
// the last item "1" shows this is not a valid encoding, and we have covered all space
// ----------------------------------------------------------------------------------------
int len = atoi(lenStr.encode().c_str());
bool coverAll = false;
svector<int_vector> options;
int_vector base;
TRACE("str", tout
<< "freeVar = " << mk_ismt2_pp(freeVar, m) << std::endl
<< "len_indicator = " << mk_ismt2_pp(len_indicator, m) << std::endl
<< "val_indicator = " << mk_ismt2_pp(val_indicator, m) << std::endl
<< "lenstr = " << lenStr << "\n"
<< "tries = " << tries << "\n";
if (m_params.m_AggressiveValueTesting) {
tout << "note: aggressive value testing is enabled" << std::endl;
}
);
if (tries == 0) {
base = int_vector(len + 1, 0);
coverAll = false;
} else {
expr * lastestValIndi = fvar_valueTester_map[freeVar][len][tries - 1].second;
TRACE("str", tout << "last value tester = " << mk_ismt2_pp(lastestValIndi, m) << std::endl;);
coverAll = get_next_val_encode(val_range_map[lastestValIndi], base);
}
long long l = (tries) * distance;
long long h = l;
for (int i = 0; i < distance; i++) {
if (coverAll)
break;
options.push_back(base);
h++;
coverAll = get_next_val_encode(options[options.size() - 1], base);
}
val_range_map[val_indicator] = options[options.size() - 1];
TRACE("str",
tout << "value tester encoding " << "{" << std::endl;
int_vector vec = val_range_map[val_indicator];
for (int_vector::iterator it = vec.begin(); it != vec.end(); ++it) {
tout << *it << std::endl;
}
tout << "}" << std::endl;
);
// ----------------------------------------------------------------------------------------
ptr_vector<expr> orList;
ptr_vector<expr> andList;
for (long long i = l; i < h; i++) {
orList.push_back(m.mk_eq(val_indicator, mk_string(longlong_to_string(i).c_str()) ));
if (m_params.m_AggressiveValueTesting) {
literal l = mk_eq(val_indicator, mk_string(longlong_to_string(i).c_str()), false);
ctx.mark_as_relevant(l);
ctx.force_phase(l);
}
zstring aStr = gen_val_string(len, options[i - l]);
expr * strAst;
if (m_params.m_UseFastValueTesterCache) {
if (!valueTesterCache.find(aStr, strAst)) {
strAst = mk_string(aStr);
valueTesterCache.insert(aStr, strAst);
m_trail.push_back(strAst);
}
} else {
strAst = mk_string(aStr);
}
andList.push_back(m.mk_eq(orList[orList.size() - 1], m.mk_eq(freeVar, strAst)));
}
if (!coverAll) {
orList.push_back(m.mk_eq(val_indicator, mk_string("more")));
if (m_params.m_AggressiveValueTesting) {
literal l = mk_eq(val_indicator, mk_string("more"), false);
ctx.mark_as_relevant(l);
ctx.force_phase(~l);
}
}
expr ** or_items = alloc_svect(expr*, orList.size());
expr ** and_items = alloc_svect(expr*, andList.size() + 1);
for (int i = 0; i < (int) orList.size(); i++) {
or_items[i] = orList[i];
}
if (orList.size() > 1)
and_items[0] = m.mk_or(orList.size(), or_items);
else
and_items[0] = or_items[0];
for (int i = 0; i < (int) andList.size(); i++) {
and_items[i + 1] = andList[i];
}
expr * valTestAssert = m.mk_and(andList.size() + 1, and_items);
// ---------------------------------------
// If the new value tester is $$_val_x_16_i
// Should add ($$_len_x_j = 16) /\ ($$_val_x_16_i = "more")
// ---------------------------------------
andList.reset();
andList.push_back(m.mk_eq(len_indicator, mk_string(lenStr)));
for (int i = 0; i < tries; i++) {
expr * vTester = fvar_valueTester_map[freeVar][len][i].second;
if (vTester != val_indicator)
andList.push_back(m.mk_eq(vTester, mk_string("more")));
}
expr * assertL = NULL;
if (andList.size() == 1) {
assertL = andList[0];
} else {
expr ** and_items = alloc_svect(expr*, andList.size());
for (int i = 0; i < (int) andList.size(); i++) {
and_items[i] = andList[i];
}
assertL = m.mk_and(andList.size(), and_items);
}
// (assertL => valTestAssert) <=> (!assertL OR valTestAssert)
valTestAssert = m.mk_or(m.mk_not(assertL), valTestAssert);
return valTestAssert;
}
expr * theory_str::gen_free_var_options(expr * freeVar, expr * len_indicator,
zstring len_valueStr, expr * valTesterInCbEq, zstring valTesterValueStr) {
ast_manager & m = get_manager();
int len = atoi(len_valueStr.encode().c_str());
// check whether any value tester is actually in scope
TRACE("str", tout << "checking scope of previous value testers" << std::endl;);
bool map_effectively_empty = true;
if (fvar_valueTester_map[freeVar].find(len) != fvar_valueTester_map[freeVar].end()) {
// there's *something* in the map, but check its scope
svector<std::pair<int, expr*> > entries = fvar_valueTester_map[freeVar][len];
for (svector<std::pair<int,expr*> >::iterator it = entries.begin(); it != entries.end(); ++it) {
std::pair<int,expr*> entry = *it;
expr * aTester = entry.second;
if (internal_variable_set.find(aTester) == internal_variable_set.end()) {
TRACE("str", tout << mk_pp(aTester, m) << " out of scope" << std::endl;);
} else {
TRACE("str", tout << mk_pp(aTester, m) << " in scope" << std::endl;);
map_effectively_empty = false;
break;
}
}
}
if (map_effectively_empty) {
TRACE("str", tout << "no previous value testers, or none of them were in scope" << std::endl;);
int tries = 0;
expr * val_indicator = mk_internal_valTest_var(freeVar, len, tries);
valueTester_fvar_map[val_indicator] = freeVar;
fvar_valueTester_map[freeVar][len].push_back(std::make_pair(sLevel, val_indicator));
print_value_tester_list(fvar_valueTester_map[freeVar][len]);
return gen_val_options(freeVar, len_indicator, val_indicator, len_valueStr, tries);
} else {
TRACE("str", tout << "checking previous value testers" << std::endl;);
print_value_tester_list(fvar_valueTester_map[freeVar][len]);
// go through all previous value testers
// If some doesn't have an eqc value, add its assertion again.
int testerTotal = fvar_valueTester_map[freeVar][len].size();
int i = 0;
for (; i < testerTotal; i++) {
expr * aTester = fvar_valueTester_map[freeVar][len][i].second;
// it's probably worth checking scope here, actually
if (internal_variable_set.find(aTester) == internal_variable_set.end()) {
TRACE("str", tout << "value tester " << mk_pp(aTester, m) << " out of scope, skipping" << std::endl;);
continue;
}
if (aTester == valTesterInCbEq) {
break;
}
bool anEqcHasValue = false;
// Z3_ast anEqc = get_eqc_value(t, aTester, anEqcHasValue);
expr * aTester_eqc_value = get_eqc_value(aTester, anEqcHasValue);
if (!anEqcHasValue) {
TRACE("str", tout << "value tester " << mk_ismt2_pp(aTester, m)
<< " doesn't have an equivalence class value." << std::endl;);
refresh_theory_var(aTester);
expr * makeupAssert = gen_val_options(freeVar, len_indicator, aTester, len_valueStr, i);
TRACE("str", tout << "var: " << mk_ismt2_pp(freeVar, m) << std::endl
<< mk_ismt2_pp(makeupAssert, m) << std::endl;);
assert_axiom(makeupAssert);
} else {
TRACE("str", tout << "value tester " << mk_ismt2_pp(aTester, m)
<< " == " << mk_ismt2_pp(aTester_eqc_value, m) << std::endl;);
}
}
if (valTesterValueStr == "more") {
expr * valTester = NULL;
if (i + 1 < testerTotal) {
valTester = fvar_valueTester_map[freeVar][len][i + 1].second;
refresh_theory_var(valTester);
} else {
valTester = mk_internal_valTest_var(freeVar, len, i + 1);
valueTester_fvar_map[valTester] = freeVar;
fvar_valueTester_map[freeVar][len].push_back(std::make_pair(sLevel, valTester));
print_value_tester_list(fvar_valueTester_map[freeVar][len]);
}
expr * nextAssert = gen_val_options(freeVar, len_indicator, valTester, len_valueStr, i + 1);
return nextAssert;
}
return NULL;
}
}
void theory_str::reduce_virtual_regex_in(expr * var, expr * regex, expr_ref_vector & items) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
TRACE("str", tout << "reduce regex " << mk_pp(regex, mgr) << " with respect to variable " << mk_pp(var, mgr) << std::endl;);
app * regexFuncDecl = to_app(regex);
if (u.re.is_to_re(regexFuncDecl)) {
// ---------------------------------------------------------
// var \in Str2Reg(s1)
// ==>
// var = s1 /\ length(var) = length(s1)
// ---------------------------------------------------------
expr * strInside = to_app(regex)->get_arg(0);
items.push_back(ctx.mk_eq_atom(var, strInside));
items.push_back(ctx.mk_eq_atom(mk_strlen(var), mk_strlen(strInside)));
return;
}
// RegexUnion
else if (u.re.is_union(regexFuncDecl)) {
// ---------------------------------------------------------
// var \in RegexUnion(r1, r2)
// ==>
// (var = newVar1 \/ var = newVar2)
// (var = newVar1 --> length(var) = length(newVar1)) /\ (var = newVar2 --> length(var) = length(newVar2))
// /\ (newVar1 \in r1) /\ (newVar2 \in r2)
// ---------------------------------------------------------
expr_ref newVar1(mk_regex_rep_var(), mgr);
expr_ref newVar2(mk_regex_rep_var(), mgr);
items.push_back(mgr.mk_or(ctx.mk_eq_atom(var, newVar1), ctx.mk_eq_atom(var, newVar2)));
items.push_back(mgr.mk_or(
mgr.mk_not(ctx.mk_eq_atom(var, newVar1)),
ctx.mk_eq_atom(mk_strlen(var), mk_strlen(newVar1))));
items.push_back(mgr.mk_or(
mgr.mk_not(ctx.mk_eq_atom(var, newVar2)),
ctx.mk_eq_atom(mk_strlen(var), mk_strlen(newVar2))));
expr * regArg1 = to_app(regex)->get_arg(0);
reduce_virtual_regex_in(newVar1, regArg1, items);
expr * regArg2 = to_app(regex)->get_arg(1);
reduce_virtual_regex_in(newVar2, regArg2, items);
return;
}
// RegexConcat
else if (u.re.is_concat(regexFuncDecl)) {
// ---------------------------------------------------------
// var \in RegexConcat(r1, r2)
// ==>
// (var = newVar1 . newVar2) /\ (length(var) = length(vewVar1 . newVar2) )
// /\ (newVar1 \in r1) /\ (newVar2 \in r2)
// ---------------------------------------------------------
expr_ref newVar1(mk_regex_rep_var(), mgr);
expr_ref newVar2(mk_regex_rep_var(), mgr);
expr_ref concatAst(mk_concat(newVar1, newVar2), mgr);
items.push_back(ctx.mk_eq_atom(var, concatAst));
items.push_back(ctx.mk_eq_atom(mk_strlen(var),
m_autil.mk_add(mk_strlen(newVar1), mk_strlen(newVar2))));
expr * regArg1 = to_app(regex)->get_arg(0);
reduce_virtual_regex_in(newVar1, regArg1, items);
expr * regArg2 = to_app(regex)->get_arg(1);
reduce_virtual_regex_in(newVar2, regArg2, items);
return;
}
// Unroll
else if (u.re.is_star(regexFuncDecl)) {
// ---------------------------------------------------------
// var \in Star(r1)
// ==>
// var = unroll(r1, t1) /\ |var| = |unroll(r1, t1)|
// ---------------------------------------------------------
expr * regArg = to_app(regex)->get_arg(0);
expr_ref unrollCnt(mk_unroll_bound_var(), mgr);
expr_ref unrollFunc(mk_unroll(regArg, unrollCnt), mgr);
items.push_back(ctx.mk_eq_atom(var, unrollFunc));
items.push_back(ctx.mk_eq_atom(mk_strlen(var), mk_strlen(unrollFunc)));
return;
}
// re.range
else if (u.re.is_range(regexFuncDecl)) {
// var in range("a", "z")
// ==>
// (var = "a" or var = "b" or ... or var = "z")
expr_ref lo(regexFuncDecl->get_arg(0), mgr);
expr_ref hi(regexFuncDecl->get_arg(1), mgr);
zstring str_lo, str_hi;
SASSERT(u.str.is_string(lo));
SASSERT(u.str.is_string(hi));
u.str.is_string(lo, str_lo);
u.str.is_string(hi, str_hi);
SASSERT(str_lo.length() == 1);
SASSERT(str_hi.length() == 1);
unsigned int c1 = str_lo[0];
unsigned int c2 = str_hi[0];
if (c1 > c2) {
// exchange
unsigned int tmp = c1;
c1 = c2;
c2 = tmp;
}
expr_ref_vector range_cases(mgr);
for (unsigned int ch = c1; ch <= c2; ++ch) {
zstring s_ch(ch);
expr_ref rhs(ctx.mk_eq_atom(var, u.str.mk_string(s_ch)), mgr);
range_cases.push_back(rhs);
}
expr_ref rhs(mk_or(range_cases), mgr);
SASSERT(rhs);
assert_axiom(rhs);
return;
} else {
get_manager().raise_exception("unrecognized regex operator");
UNREACHABLE();
}
}
void theory_str::gen_assign_unroll_reg(std::set<expr*> & unrolls) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
expr_ref_vector items(mgr);
for (std::set<expr*>::iterator itor = unrolls.begin(); itor != unrolls.end(); itor++) {
expr * unrFunc = *itor;
TRACE("str", tout << "generating assignment for unroll " << mk_pp(unrFunc, mgr) << std::endl;);
expr * regexInUnr = to_app(unrFunc)->get_arg(0);
expr * cntInUnr = to_app(unrFunc)->get_arg(1);
items.reset();
rational low, high;
bool low_exists = lower_bound(cntInUnr, low);
bool high_exists = upper_bound(cntInUnr, high);
TRACE("str",
tout << "unroll " << mk_pp(unrFunc, mgr) << std::endl;
rational unrLenValue;
bool unrLenValue_exists = get_len_value(unrFunc, unrLenValue);
tout << "unroll length: " << (unrLenValue_exists ? unrLenValue.to_string() : "?") << std::endl;
rational cntInUnrValue;
bool cntHasValue = get_value(cntInUnr, cntInUnrValue);
tout << "unroll count: " << (cntHasValue ? cntInUnrValue.to_string() : "?")
<< " low = "
<< (low_exists ? low.to_string() : "?")
<< " high = "
<< (high_exists ? high.to_string() : "?")
<< std::endl;
);
expr_ref toAssert(mgr);
if (low.is_neg()) {
toAssert = m_autil.mk_ge(cntInUnr, mk_int(0));
} else {
if (unroll_var_map.find(unrFunc) == unroll_var_map.end()) {
expr_ref newVar1(mk_regex_rep_var(), mgr);
expr_ref newVar2(mk_regex_rep_var(), mgr);
expr_ref concatAst(mk_concat(newVar1, newVar2), mgr);
expr_ref newCnt(mk_unroll_bound_var(), mgr);
expr_ref newUnrollFunc(mk_unroll(regexInUnr, newCnt), mgr);
// unroll(r1, t1) = newVar1 . newVar2
items.push_back(ctx.mk_eq_atom(unrFunc, concatAst));
items.push_back(ctx.mk_eq_atom(mk_strlen(unrFunc), m_autil.mk_add(mk_strlen(newVar1), mk_strlen(newVar2))));
// mk_strlen(unrFunc) >= mk_strlen(newVar{1,2})
items.push_back(m_autil.mk_ge(m_autil.mk_add(mk_strlen(unrFunc), m_autil.mk_mul(mk_int(-1), mk_strlen(newVar1))), mk_int(0)));
items.push_back(m_autil.mk_ge(m_autil.mk_add(mk_strlen(unrFunc), m_autil.mk_mul(mk_int(-1), mk_strlen(newVar2))), mk_int(0)));
// newVar1 \in r1
reduce_virtual_regex_in(newVar1, regexInUnr, items);
items.push_back(ctx.mk_eq_atom(cntInUnr, m_autil.mk_add(newCnt, mk_int(1))));
items.push_back(ctx.mk_eq_atom(newVar2, newUnrollFunc));
items.push_back(ctx.mk_eq_atom(mk_strlen(newVar2), mk_strlen(newUnrollFunc)));
toAssert = ctx.mk_eq_atom(
m_autil.mk_ge(cntInUnr, mk_int(1)),
mk_and(items));
// option 0
expr_ref op0(ctx.mk_eq_atom(cntInUnr, mk_int(0)), mgr);
expr_ref ast1(ctx.mk_eq_atom(unrFunc, mk_string("")), mgr);
expr_ref ast2(ctx.mk_eq_atom(mk_strlen(unrFunc), mk_int(0)), mgr);
expr_ref and1(mgr.mk_and(ast1, ast2), mgr);
// put together
toAssert = mgr.mk_and(ctx.mk_eq_atom(op0, and1), toAssert);
unroll_var_map[unrFunc] = toAssert;
} else {
toAssert = unroll_var_map[unrFunc];
}
}
m_trail.push_back(toAssert);
assert_axiom(toAssert);
}
}
static int computeGCD(int x, int y) {
if (x == 0) {
return y;
}
while (y != 0) {
if (x > y) {
x = x - y;
} else {
y = y - x;
}
}
return x;
}
static int computeLCM(int a, int b) {
int temp = computeGCD(a, b);
return temp ? (a / temp * b) : 0;
}
static zstring get_unrolled_string(zstring core, int count) {
zstring res("");
for (int i = 0; i < count; i++) {
res = res + core;
}
return res;
}
expr * theory_str::gen_assign_unroll_Str2Reg(expr * n, std::set<expr*> & unrolls) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
int lcm = 1;
int coreValueCount = 0;
expr * oneUnroll = NULL;
zstring oneCoreStr("");
for (std::set<expr*>::iterator itor = unrolls.begin(); itor != unrolls.end(); itor++) {
expr * str2RegFunc = to_app(*itor)->get_arg(0);
expr * coreVal = to_app(str2RegFunc)->get_arg(0);
zstring coreStr;
u.str.is_string(coreVal, coreStr);
if (oneUnroll == NULL) {
oneUnroll = *itor;
oneCoreStr = coreStr;
}
coreValueCount++;
int core1Len = coreStr.length();
lcm = computeLCM(lcm, core1Len);
}
//
bool canHaveNonEmptyAssign = true;
expr_ref_vector litems(mgr);
zstring lcmStr = get_unrolled_string(oneCoreStr, (lcm / oneCoreStr.length()));
for (std::set<expr*>::iterator itor = unrolls.begin(); itor != unrolls.end(); itor++) {
expr * str2RegFunc = to_app(*itor)->get_arg(0);
expr * coreVal = to_app(str2RegFunc)->get_arg(0);
zstring coreStr;
u.str.is_string(coreVal, coreStr);
unsigned int core1Len = coreStr.length();
zstring uStr = get_unrolled_string(coreStr, (lcm / core1Len));
if (uStr != lcmStr) {
canHaveNonEmptyAssign = false;
}
litems.push_back(ctx.mk_eq_atom(n, *itor));
}
if (canHaveNonEmptyAssign) {
return gen_unroll_conditional_options(n, unrolls, lcmStr);
} else {
expr_ref implyL(mk_and(litems), mgr);
expr_ref implyR(ctx.mk_eq_atom(n, mk_string("")), mgr);
// want to return (implyL -> implyR)
expr * final_axiom = rewrite_implication(implyL, implyR);
return final_axiom;
}
}
expr * theory_str::gen_unroll_conditional_options(expr * var, std::set<expr*> & unrolls, zstring lcmStr) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
int dist = opt_LCMUnrollStep;
expr_ref_vector litems(mgr);
expr_ref moreAst(mk_string("more"), mgr);
for (std::set<expr*>::iterator itor = unrolls.begin(); itor != unrolls.end(); itor++) {
expr_ref item(ctx.mk_eq_atom(var, *itor), mgr);
TRACE("str", tout << "considering unroll " << mk_pp(item, mgr) << std::endl;);
litems.push_back(item);
}
// handle out-of-scope entries in unroll_tries_map
ptr_vector<expr> outOfScopeTesters;
for (ptr_vector<expr>::iterator it = unroll_tries_map[var][unrolls].begin();
it != unroll_tries_map[var][unrolls].end(); ++it) {
expr * tester = *it;
bool inScope = (internal_unrollTest_vars.find(tester) != internal_unrollTest_vars.end());
TRACE("str", tout << "unroll test var " << mk_pp(tester, mgr)
<< (inScope ? " in scope" : " out of scope")
<< std::endl;);
if (!inScope) {
outOfScopeTesters.push_back(tester);
}
}
for (ptr_vector<expr>::iterator it = outOfScopeTesters.begin();
it != outOfScopeTesters.end(); ++it) {
unroll_tries_map[var][unrolls].erase(*it);
}
if (unroll_tries_map[var][unrolls].size() == 0) {
unroll_tries_map[var][unrolls].push_back(mk_unroll_test_var());
}
int tries = unroll_tries_map[var][unrolls].size();
for (int i = 0; i < tries; i++) {
expr * tester = unroll_tries_map[var][unrolls][i];
// TESTING
refresh_theory_var(tester);
bool testerHasValue = false;
expr * testerVal = get_eqc_value(tester, testerHasValue);
if (!testerHasValue) {
// generate make-up assertion
int l = i * dist;
int h = (i + 1) * dist;
expr_ref lImp(mk_and(litems), mgr);
expr_ref rImp(gen_unroll_assign(var, lcmStr, tester, l, h), mgr);
SASSERT(lImp);
TRACE("str", tout << "lImp = " << mk_pp(lImp, mgr) << std::endl;);
SASSERT(rImp);
TRACE("str", tout << "rImp = " << mk_pp(rImp, mgr) << std::endl;);
expr_ref toAssert(mgr.mk_or(mgr.mk_not(lImp), rImp), mgr);
SASSERT(toAssert);
TRACE("str", tout << "Making up assignments for variable which is equal to unbounded Unroll" << std::endl;);
m_trail.push_back(toAssert);
return toAssert;
// note: this is how the code looks in Z3str2's strRegex.cpp:genUnrollConditionalOptions.
// the return is in the same place
// insert [tester = "more"] to litems so that the implyL for next tester is correct
litems.push_back(ctx.mk_eq_atom(tester, moreAst));
} else {
zstring testerStr;
u.str.is_string(testerVal, testerStr);
TRACE("str", tout << "Tester [" << mk_pp(tester, mgr) << "] = " << testerStr << "\n";);
if (testerStr == "more") {
litems.push_back(ctx.mk_eq_atom(tester, moreAst));
}
}
}
expr * tester = mk_unroll_test_var();
unroll_tries_map[var][unrolls].push_back(tester);
int l = tries * dist;
int h = (tries + 1) * dist;
expr_ref lImp(mk_and(litems), mgr);
expr_ref rImp(gen_unroll_assign(var, lcmStr, tester, l, h), mgr);
SASSERT(lImp);
SASSERT(rImp);
expr_ref toAssert(mgr.mk_or(mgr.mk_not(lImp), rImp), mgr);
SASSERT(toAssert);
TRACE("str", tout << "Generating assignment for variable which is equal to unbounded Unroll" << std::endl;);
m_trail.push_back(toAssert);
return toAssert;
}
expr * theory_str::gen_unroll_assign(expr * var, zstring lcmStr, expr * testerVar, int l, int h) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
TRACE("str", tout << "entry: var = " << mk_pp(var, mgr) << ", lcmStr = " << lcmStr
<< ", l = " << l << ", h = " << h << "\n";);
if (m_params.m_AggressiveUnrollTesting) {
TRACE("str", tout << "note: aggressive unroll testing is active" << std::endl;);
}
expr_ref_vector orItems(mgr);
expr_ref_vector andItems(mgr);
for (int i = l; i < h; i++) {
zstring iStr = int_to_string(i);
expr_ref testerEqAst(ctx.mk_eq_atom(testerVar, mk_string(iStr)), mgr);
TRACE("str", tout << "testerEqAst = " << mk_pp(testerEqAst, mgr) << std::endl;);
if (m_params.m_AggressiveUnrollTesting) {
literal l = mk_eq(testerVar, mk_string(iStr), false);
ctx.mark_as_relevant(l);
ctx.force_phase(l);
}
orItems.push_back(testerEqAst);
zstring unrollStrInstance = get_unrolled_string(lcmStr, i);
expr_ref x1(ctx.mk_eq_atom(testerEqAst, ctx.mk_eq_atom(var, mk_string(unrollStrInstance))), mgr);
TRACE("str", tout << "x1 = " << mk_pp(x1, mgr) << std::endl;);
andItems.push_back(x1);
expr_ref x2(ctx.mk_eq_atom(testerEqAst, ctx.mk_eq_atom(mk_strlen(var), mk_int(i * lcmStr.length()))), mgr);
TRACE("str", tout << "x2 = " << mk_pp(x2, mgr) << std::endl;);
andItems.push_back(x2);
}
expr_ref testerEqMore(ctx.mk_eq_atom(testerVar, mk_string("more")), mgr);
TRACE("str", tout << "testerEqMore = " << mk_pp(testerEqMore, mgr) << std::endl;);
if (m_params.m_AggressiveUnrollTesting) {
literal l = mk_eq(testerVar, mk_string("more"), false);
ctx.mark_as_relevant(l);
ctx.force_phase(~l);
}
orItems.push_back(testerEqMore);
int nextLowerLenBound = h * lcmStr.length();
expr_ref more2(ctx.mk_eq_atom(testerEqMore,
//Z3_mk_ge(mk_length(t, var), mk_int(ctx, nextLowerLenBound))
m_autil.mk_ge(m_autil.mk_add(mk_strlen(var), mk_int(-1 * nextLowerLenBound)), mk_int(0))
), mgr);
TRACE("str", tout << "more2 = " << mk_pp(more2, mgr) << std::endl;);
andItems.push_back(more2);
expr_ref finalOR(mgr.mk_or(orItems.size(), orItems.c_ptr()), mgr);
TRACE("str", tout << "finalOR = " << mk_pp(finalOR, mgr) << std::endl;);
andItems.push_back(mk_or(orItems));
expr_ref finalAND(mgr.mk_and(andItems.size(), andItems.c_ptr()), mgr);
TRACE("str", tout << "finalAND = " << mk_pp(finalAND, mgr) << std::endl;);
// doing the following avoids a segmentation fault
m_trail.push_back(finalAND);
return finalAND;
}
expr * theory_str::gen_len_test_options(expr * freeVar, expr * indicator, int tries) {
ast_manager & m = get_manager();
context & ctx = get_context();
expr_ref freeVarLen(mk_strlen(freeVar), m);
SASSERT(freeVarLen);
expr_ref_vector orList(m);
expr_ref_vector andList(m);
int distance = 3;
int l = (tries - 1) * distance;
int h = tries * distance;
TRACE("str",
tout << "building andList and orList" << std::endl;
if (m_params.m_AggressiveLengthTesting) {
tout << "note: aggressive length testing is active" << std::endl;
}
);
// experimental theory-aware case split support
literal_vector case_split_literals;
for (int i = l; i < h; ++i) {
expr_ref str_indicator(m);
if (m_params.m_UseFastLengthTesterCache) {
rational ri(i);
expr * lookup_val;
if(lengthTesterCache.find(ri, lookup_val)) {
str_indicator = expr_ref(lookup_val, m);
} else {
// no match; create and insert
zstring i_str = int_to_string(i);
expr_ref new_val(mk_string(i_str), m);
lengthTesterCache.insert(ri, new_val);
m_trail.push_back(new_val);
str_indicator = expr_ref(new_val, m);
}
} else {
zstring i_str = int_to_string(i);
str_indicator = expr_ref(mk_string(i_str), m);
}
expr_ref or_expr(ctx.mk_eq_atom(indicator, str_indicator), m);
orList.push_back(or_expr);
double priority;
// give high priority to small lengths if this is available
if (i <= 5) {
priority = 0.3;
} else {
// prioritize over "more"
priority = 0.2;
}
add_theory_aware_branching_info(or_expr, priority, l_true);
if (m_params.m_AggressiveLengthTesting) {
literal l = mk_eq(indicator, str_indicator, false);
ctx.mark_as_relevant(l);
ctx.force_phase(l);
}
case_split_literals.insert(mk_eq(freeVarLen, mk_int(i), false));
expr_ref and_expr(ctx.mk_eq_atom(orList.get(orList.size() - 1), m.mk_eq(freeVarLen, mk_int(i))), m);
andList.push_back(and_expr);
}
expr_ref more_option(ctx.mk_eq_atom(indicator, mk_string("more")), m);
orList.push_back(more_option);
// decrease priority of this option
add_theory_aware_branching_info(more_option, -0.1, l_true);
if (m_params.m_AggressiveLengthTesting) {
literal l = mk_eq(indicator, mk_string("more"), false);
ctx.mark_as_relevant(l);
ctx.force_phase(~l);
}
andList.push_back(ctx.mk_eq_atom(orList.get(orList.size() - 1), m_autil.mk_ge(freeVarLen, mk_int(h))));
/*
{ // more experimental theory case split support
expr_ref tmp(m_autil.mk_ge(freeVarLen, mk_int(h)), m);
ctx.internalize(m_autil.mk_ge(freeVarLen, mk_int(h)), false);
case_split_literals.push_back(ctx.get_literal(tmp));
ctx.mk_th_case_split(case_split_literals.size(), case_split_literals.c_ptr());
}
*/
expr_ref_vector or_items(m);
expr_ref_vector and_items(m);
for (unsigned i = 0; i < orList.size(); ++i) {
or_items.push_back(orList.get(i));
}
and_items.push_back(mk_or(or_items));
for(unsigned i = 0; i < andList.size(); ++i) {
and_items.push_back(andList.get(i));
}
TRACE("str", tout << "check: " << mk_pp(mk_and(and_items), m) << std::endl;);
expr_ref lenTestAssert = mk_and(and_items);
SASSERT(lenTestAssert);
TRACE("str", tout << "crash avoidance lenTestAssert: " << mk_pp(lenTestAssert, m) << std::endl;);
int testerCount = tries - 1;
if (testerCount > 0) {
expr_ref_vector and_items_LHS(m);
expr_ref moreAst(mk_string("more"), m);
for (int i = 0; i < testerCount; ++i) {
expr * indicator = fvar_lenTester_map[freeVar][i];
if (internal_variable_set.find(indicator) == internal_variable_set.end()) {
TRACE("str", tout << "indicator " << mk_pp(indicator, m) << " out of scope; continuing" << std::endl;);
continue;
} else {
TRACE("str", tout << "indicator " << mk_pp(indicator, m) << " in scope" << std::endl;);
and_items_LHS.push_back(ctx.mk_eq_atom(indicator, moreAst));
}
}
expr_ref assertL(mk_and(and_items_LHS), m);
SASSERT(assertL);
expr * finalAxiom = m.mk_or(m.mk_not(assertL), lenTestAssert.get());
SASSERT(finalAxiom != NULL);
TRACE("str", tout << "crash avoidance finalAxiom: " << mk_pp(finalAxiom, m) << std::endl;);
return finalAxiom;
} else {
TRACE("str", tout << "crash avoidance lenTestAssert.get(): " << mk_pp(lenTestAssert.get(), m) << std::endl;);
m_trail.push_back(lenTestAssert.get());
return lenTestAssert.get();
}
}
// Return an expression of the form
// (tester = "less" | tester = "N" | tester = "more") &
// (tester = "less" iff len(freeVar) < N) & (tester = "more" iff len(freeVar) > N) & (tester = "N" iff len(freeVar) = N))
expr_ref theory_str::binary_search_case_split(expr * freeVar, expr * tester, binary_search_info & bounds, literal_vector & case_split) {
context & ctx = get_context();
ast_manager & m = get_manager();
rational N = bounds.midPoint;
rational N_minus_one = N - rational::one();
rational N_plus_one = N + rational::one();
expr_ref lenFreeVar(mk_strlen(freeVar), m);
TRACE("str", tout << "create case split for free var " << mk_pp(freeVar, m)
<< " over " << mk_pp(tester, m) << " with midpoint " << N << std::endl;);
expr_ref_vector combinedCaseSplit(m);
expr_ref_vector testerCases(m);
expr_ref caseLess(ctx.mk_eq_atom(tester, mk_string("less")), m);
testerCases.push_back(caseLess);
combinedCaseSplit.push_back(ctx.mk_eq_atom(caseLess, m_autil.mk_le(lenFreeVar, m_autil.mk_numeral(N_minus_one, true) )));
expr_ref caseMore(ctx.mk_eq_atom(tester, mk_string("more")), m);
testerCases.push_back(caseMore);
combinedCaseSplit.push_back(ctx.mk_eq_atom(caseMore, m_autil.mk_ge(lenFreeVar, m_autil.mk_numeral(N_plus_one, true) )));
expr_ref caseEq(ctx.mk_eq_atom(tester, mk_string(N.to_string().c_str())), m);
testerCases.push_back(caseEq);
combinedCaseSplit.push_back(ctx.mk_eq_atom(caseEq, ctx.mk_eq_atom(lenFreeVar, m_autil.mk_numeral(N, true))));
combinedCaseSplit.push_back(mk_or(testerCases));
// force internalization on all terms in testerCases so we can extract literals
for (unsigned i = 0; i < testerCases.size(); ++i) {
expr * testerCase = testerCases.get(i);
if (!ctx.b_internalized(testerCase)) {
ctx.internalize(testerCase, false);
}
literal l = ctx.get_literal(testerCase);
case_split.push_back(l);
}
expr_ref final_term(mk_and(combinedCaseSplit), m);
SASSERT(final_term);
TRACE("str", tout << "final term: " << mk_pp(final_term, m) << std::endl;);
return final_term;
}
expr * theory_str::binary_search_length_test(expr * freeVar, expr * previousLenTester, zstring previousLenTesterValue) {
ast_manager & m = get_manager();
if (binary_search_len_tester_stack.contains(freeVar) && !binary_search_len_tester_stack[freeVar].empty()) {
TRACE("str", tout << "checking existing length testers for " << mk_pp(freeVar, m) << std::endl;
for (ptr_vector<expr>::const_iterator it = binary_search_len_tester_stack[freeVar].begin();
it != binary_search_len_tester_stack[freeVar].end(); ++it) {
expr * tester = *it;
tout << mk_pp(tester, m) << ": ";
if (binary_search_len_tester_info.contains(tester)) {
binary_search_info & bounds = binary_search_len_tester_info[tester];
tout << "[" << bounds.lowerBound << " | " << bounds.midPoint << " | " << bounds.upperBound << "]!" << bounds.windowSize;
} else {
tout << "[WARNING: no bounds info available]";
}
bool hasEqcValue;
expr * testerEqcValue = get_eqc_value(tester, hasEqcValue);
if (hasEqcValue) {
tout << " = " << mk_pp(testerEqcValue, m);
} else {
tout << " [no eqc value]";
}
tout << std::endl;
}
);
expr * lastTester = binary_search_len_tester_stack[freeVar].back();
bool lastTesterHasEqcValue;
expr * lastTesterValue = get_eqc_value(lastTester, lastTesterHasEqcValue);
zstring lastTesterConstant;
if (!lastTesterHasEqcValue) {
TRACE("str", tout << "length tester " << mk_pp(lastTester, m) << " at top of stack doesn't have an EQC value yet" << std::endl;);
// check previousLenTester
if (previousLenTester == lastTester) {
lastTesterConstant = previousLenTesterValue;
TRACE("str", tout << "invoked with previousLenTester info matching top of stack" << std::endl;);
} else {
TRACE("str", tout << "WARNING: unexpected reordering of length testers!" << std::endl;);
UNREACHABLE(); return NULL;
}
} else {
u.str.is_string(lastTesterValue, lastTesterConstant);
}
TRACE("str", tout << "last length tester is assigned \"" << lastTesterConstant << "\"" << "\n";);
if (lastTesterConstant == "more" || lastTesterConstant == "less") {
// use the previous bounds info to generate a new midpoint
binary_search_info lastBounds;
if (!binary_search_len_tester_info.find(lastTester, lastBounds)) {
// unexpected
TRACE("str", tout << "WARNING: no bounds information available for last tester!" << std::endl;);
UNREACHABLE();
}
TRACE("str", tout << "last bounds are [" << lastBounds.lowerBound << " | " << lastBounds.midPoint << " | " << lastBounds.upperBound << "]!" << lastBounds.windowSize << std::endl;);
binary_search_info newBounds;
expr * newTester = 0;
if (lastTesterConstant == "more") {
// special case: if the midpoint, upper bound, and window size are all equal,
// we double the window size and adjust the bounds
if (lastBounds.midPoint == lastBounds.upperBound && lastBounds.upperBound == lastBounds.windowSize) {
TRACE("str", tout << "search hit window size; expanding" << std::endl;);
newBounds.lowerBound = lastBounds.windowSize + rational::one();
newBounds.windowSize = lastBounds.windowSize * rational(2);
newBounds.upperBound = newBounds.windowSize;
newBounds.calculate_midpoint();
} else if (false) {
// handle the case where the midpoint can't be increased further
// (e.g. a window like [50 | 50 | 50]!64 and we don't answer "50")
} else {
// general case
newBounds.lowerBound = lastBounds.midPoint + rational::one();
newBounds.windowSize = lastBounds.windowSize;
newBounds.upperBound = lastBounds.upperBound;
newBounds.calculate_midpoint();
}
if (!binary_search_next_var_high.find(lastTester, newTester)) {
newTester = mk_internal_lenTest_var(freeVar, newBounds.midPoint.get_int32());
binary_search_next_var_high.insert(lastTester, newTester);
}
refresh_theory_var(newTester);
} else if (lastTesterConstant == "less") {
if (false) {
// handle the case where the midpoint can't be decreased further
// (e.g. a window like [0 | 0 | 0]!64 and we don't answer "0"
} else {
// general case
newBounds.upperBound = lastBounds.midPoint - rational::one();
newBounds.windowSize = lastBounds.windowSize;
newBounds.lowerBound = lastBounds.lowerBound;
newBounds.calculate_midpoint();
}
if (!binary_search_next_var_low.find(lastTester, newTester)) {
newTester = mk_internal_lenTest_var(freeVar, newBounds.midPoint.get_int32());
binary_search_next_var_low.insert(lastTester, newTester);
}
refresh_theory_var(newTester);
}
TRACE("str", tout << "new bounds are [" << newBounds.lowerBound << " | " << newBounds.midPoint << " | " << newBounds.upperBound << "]!" << newBounds.windowSize << std::endl;);
binary_search_len_tester_stack[freeVar].push_back(newTester);
m_trail_stack.push(binary_search_trail<theory_str>(binary_search_len_tester_stack, freeVar));
binary_search_len_tester_info.insert(newTester, newBounds);
m_trail_stack.push(insert_obj_map<theory_str, expr, binary_search_info>(binary_search_len_tester_info, newTester));
literal_vector case_split_literals;
expr_ref next_case_split(binary_search_case_split(freeVar, newTester, newBounds, case_split_literals));
m_trail.push_back(next_case_split);
// ctx.mk_th_case_split(case_split_literals.size(), case_split_literals.c_ptr());
return next_case_split;
} else { // lastTesterConstant is a concrete value
TRACE("str", tout << "length is fixed; generating models for free var" << std::endl;);
// defensive check that this length did not converge on a negative value.
binary_search_info lastBounds;
if (!binary_search_len_tester_info.find(lastTester, lastBounds)) {
// unexpected
TRACE("str", tout << "WARNING: no bounds information available for last tester!" << std::endl;);
UNREACHABLE();
}
if (lastBounds.midPoint.is_neg()) {
TRACE("str", tout << "WARNING: length search converged on a negative value. Negating this constraint." << std::endl;);
expr_ref axiom(m_autil.mk_ge(mk_strlen(freeVar), m_autil.mk_numeral(rational::zero(), true)), m);
return axiom;
}
// length is fixed
expr * valueAssert = gen_free_var_options(freeVar, lastTester, lastTesterConstant, NULL, zstring(""));
return valueAssert;
}
} else {
// no length testers yet
TRACE("str", tout << "no length testers for " << mk_pp(freeVar, m) << std::endl;);
binary_search_len_tester_stack.insert(freeVar, ptr_vector<expr>());
expr * firstTester;
rational lowerBound(0);
rational upperBound(m_params.m_BinarySearchInitialUpperBound);
rational windowSize(upperBound);
rational midPoint(floor(upperBound / rational(2)));
if (!binary_search_starting_len_tester.find(freeVar, firstTester)) {
firstTester = mk_internal_lenTest_var(freeVar, midPoint.get_int32());
binary_search_starting_len_tester.insert(freeVar, firstTester);
}
refresh_theory_var(firstTester);
binary_search_len_tester_stack[freeVar].push_back(firstTester);
m_trail_stack.push(binary_search_trail<theory_str>(binary_search_len_tester_stack, freeVar));
binary_search_info new_info(lowerBound, midPoint, upperBound, windowSize);
binary_search_len_tester_info.insert(firstTester, new_info);
m_trail_stack.push(insert_obj_map<theory_str, expr, binary_search_info>(binary_search_len_tester_info, firstTester));
literal_vector case_split_literals;
expr_ref initial_case_split(binary_search_case_split(freeVar, firstTester, new_info, case_split_literals));
m_trail.push_back(initial_case_split);
// ctx.mk_th_case_split(case_split_literals.size(), case_split_literals.c_ptr());
return initial_case_split;
}
}
// -----------------------------------------------------------------------------------------------------
// True branch will be taken in final_check:
// - When we discover a variable is "free" for the first time
// lenTesterInCbEq = NULL
// lenTesterValue = ""
// False branch will be taken when invoked by new_eq_eh().
// - After we set up length tester for a "free" var in final_check,
// when the tester is assigned to some value (e.g. "more" or "4"),
// lenTesterInCbEq != NULL, and its value will be passed by lenTesterValue
// The difference is that in new_eq_eh(), lenTesterInCbEq and its value have NOT been put into a same eqc
// -----------------------------------------------------------------------------------------------------
expr * theory_str::gen_len_val_options_for_free_var(expr * freeVar, expr * lenTesterInCbEq, zstring lenTesterValue) {
ast_manager & m = get_manager();
TRACE("str", tout << "gen for free var " << mk_ismt2_pp(freeVar, m) << std::endl;);
if (m_params.m_UseBinarySearch) {
TRACE("str", tout << "using binary search heuristic" << std::endl;);
return binary_search_length_test(freeVar, lenTesterInCbEq, lenTesterValue);
} else {
bool map_effectively_empty = false;
if (!fvar_len_count_map.contains(freeVar)) {
TRACE("str", tout << "fvar_len_count_map is empty" << std::endl;);
map_effectively_empty = true;
}
if (!map_effectively_empty) {
// check whether any entries correspond to variables that went out of scope;
// if every entry is out of scope then the map counts as being empty
// assume empty and find a counterexample
map_effectively_empty = true;
ptr_vector<expr> indicator_set = fvar_lenTester_map[freeVar];
for (ptr_vector<expr>::iterator it = indicator_set.begin(); it != indicator_set.end(); ++it) {
expr * indicator = *it;
if (internal_variable_set.find(indicator) != internal_variable_set.end()) {
TRACE("str", tout <<"found active internal variable " << mk_ismt2_pp(indicator, m)
<< " in fvar_lenTester_map[freeVar]" << std::endl;);
map_effectively_empty = false;
break;
}
}
CTRACE("str", map_effectively_empty, tout << "all variables in fvar_lenTester_map[freeVar] out of scope" << std::endl;);
}
if (map_effectively_empty) {
// no length assertions for this free variable have ever been added.
TRACE("str", tout << "no length assertions yet" << std::endl;);
fvar_len_count_map.insert(freeVar, 1);
unsigned int testNum = fvar_len_count_map[freeVar];
expr_ref indicator(mk_internal_lenTest_var(freeVar, testNum), m);
SASSERT(indicator);
// since the map is "effectively empty", we can remove those variables that have left scope...
fvar_lenTester_map[freeVar].shrink(0);
fvar_lenTester_map[freeVar].push_back(indicator);
lenTester_fvar_map.insert(indicator, freeVar);
expr * lenTestAssert = gen_len_test_options(freeVar, indicator, testNum);
SASSERT(lenTestAssert != NULL);
return lenTestAssert;
} else {
TRACE("str", tout << "found previous in-scope length assertions" << std::endl;);
expr * effectiveLenInd = NULL;
zstring effectiveLenIndiStr("");
int lenTesterCount = (int) fvar_lenTester_map[freeVar].size();
TRACE("str",
tout << lenTesterCount << " length testers in fvar_lenTester_map[" << mk_pp(freeVar, m) << "]:" << std::endl;
for (int i = 0; i < lenTesterCount; ++i) {
expr * len_indicator = fvar_lenTester_map[freeVar][i];
tout << mk_pp(len_indicator, m) << ": ";
bool effectiveInScope = (internal_variable_set.find(len_indicator) != internal_variable_set.end());
tout << (effectiveInScope ? "in scope" : "NOT in scope");
tout << std::endl;
}
);
int i = 0;
for (; i < lenTesterCount; ++i) {
expr * len_indicator_pre = fvar_lenTester_map[freeVar][i];
// check whether this is in scope as well
if (internal_variable_set.find(len_indicator_pre) == internal_variable_set.end()) {
TRACE("str", tout << "length indicator " << mk_pp(len_indicator_pre, m) << " not in scope" << std::endl;);
continue;
}
bool indicatorHasEqcValue = false;
expr * len_indicator_value = get_eqc_value(len_indicator_pre, indicatorHasEqcValue);
TRACE("str", tout << "length indicator " << mk_ismt2_pp(len_indicator_pre, m) <<
" = " << mk_ismt2_pp(len_indicator_value, m) << std::endl;);
if (indicatorHasEqcValue) {
zstring len_pIndiStr;
u.str.is_string(len_indicator_value, len_pIndiStr);
if (len_pIndiStr != "more") {
effectiveLenInd = len_indicator_pre;
effectiveLenIndiStr = len_pIndiStr;
break;
}
} else {
if (lenTesterInCbEq != len_indicator_pre) {
TRACE("str", tout << "WARNING: length indicator " << mk_ismt2_pp(len_indicator_pre, m)
<< " does not have an equivalence class value."
<< " i = " << i << ", lenTesterCount = " << lenTesterCount << std::endl;);
if (i > 0) {
effectiveLenInd = fvar_lenTester_map[freeVar][i - 1];
bool effectiveHasEqcValue;
expr * effective_eqc_value = get_eqc_value(effectiveLenInd, effectiveHasEqcValue);
bool effectiveInScope = (internal_variable_set.find(effectiveLenInd) != internal_variable_set.end());
TRACE("str", tout << "checking effective length indicator " << mk_pp(effectiveLenInd, m) << ": "
<< (effectiveInScope ? "in scope" : "NOT in scope") << ", ";
if (effectiveHasEqcValue) {
tout << "~= " << mk_pp(effective_eqc_value, m);
} else {
tout << "no eqc string constant";
}
tout << std::endl;);
if (effectiveLenInd == lenTesterInCbEq) {
effectiveLenIndiStr = lenTesterValue;
} else {
if (effectiveHasEqcValue) {
u.str.is_string(effective_eqc_value, effectiveLenIndiStr);
} else {
NOT_IMPLEMENTED_YET();
}
}
}
break;
}
// lenTesterInCbEq == len_indicator_pre
else {
if (lenTesterValue != "more") {
effectiveLenInd = len_indicator_pre;
effectiveLenIndiStr = lenTesterValue;
break;
}
}
} // !indicatorHasEqcValue
} // for (i : [0..lenTesterCount-1])
if (effectiveLenIndiStr == "more" || effectiveLenIndiStr == "") {
TRACE("str", tout << "length is not fixed; generating length tester options for free var" << std::endl;);
expr_ref indicator(m);
unsigned int testNum = 0;
TRACE("str", tout << "effectiveLenIndiStr = " << effectiveLenIndiStr
<< ", i = " << i << ", lenTesterCount = " << lenTesterCount << "\n";);
if (i == lenTesterCount) {
fvar_len_count_map[freeVar] = fvar_len_count_map[freeVar] + 1;
testNum = fvar_len_count_map[freeVar];
indicator = mk_internal_lenTest_var(freeVar, testNum);
fvar_lenTester_map[freeVar].push_back(indicator);
lenTester_fvar_map.insert(indicator, freeVar);
} else {
indicator = fvar_lenTester_map[freeVar][i];
refresh_theory_var(indicator);
testNum = i + 1;
}
expr * lenTestAssert = gen_len_test_options(freeVar, indicator, testNum);
SASSERT(lenTestAssert != NULL);
return lenTestAssert;
} else {
TRACE("str", tout << "length is fixed; generating models for free var" << std::endl;);
// length is fixed
expr * valueAssert = gen_free_var_options(freeVar, effectiveLenInd, effectiveLenIndiStr, NULL, zstring(""));
return valueAssert;
}
} // fVarLenCountMap.find(...)
} // !UseBinarySearch
}
void theory_str::get_concats_in_eqc(expr * n, std::set<expr*> & concats) {
expr * eqcNode = n;
do {
if (u.str.is_concat(to_app(eqcNode))) {
concats.insert(eqcNode);
}
eqcNode = get_eqc_next(eqcNode);
} while (eqcNode != n);
}
void theory_str::get_var_in_eqc(expr * n, std::set<expr*> & varSet) {
expr * eqcNode = n;
do {
if (variable_set.find(eqcNode) != variable_set.end()) {
varSet.insert(eqcNode);
}
eqcNode = get_eqc_next(eqcNode);
} while (eqcNode != n);
}
bool cmpvarnames(expr * lhs, expr * rhs) {
symbol lhs_name = to_app(lhs)->get_decl()->get_name();
symbol rhs_name = to_app(rhs)->get_decl()->get_name();
return lhs_name.str() < rhs_name.str();
}
void theory_str::process_free_var(std::map<expr*, int> & freeVar_map) {
context & ctx = get_context();
ast_manager & m = get_manager();
std::set<expr*> eqcRepSet;
std::set<expr*> leafVarSet;
std::map<int, std::set<expr*> > aloneVars;
for (std::map<expr*, int>::iterator fvIt = freeVar_map.begin(); fvIt != freeVar_map.end(); fvIt++) {
expr * freeVar = fvIt->first;
// skip all regular expression vars
if (regex_variable_set.find(freeVar) != regex_variable_set.end()) {
continue;
}
// Iterate the EQC of freeVar, its eqc variable should not be in the eqcRepSet.
// If found, have to filter it out
std::set<expr*> eqVarSet;
get_var_in_eqc(freeVar, eqVarSet);
bool duplicated = false;
expr * dupVar = NULL;
for (std::set<expr*>::iterator itorEqv = eqVarSet.begin(); itorEqv != eqVarSet.end(); itorEqv++) {
if (eqcRepSet.find(*itorEqv) != eqcRepSet.end()) {
duplicated = true;
dupVar = *itorEqv;
break;
}
}
if (duplicated && dupVar != NULL) {
TRACE("str", tout << "Duplicated free variable found:" << mk_ismt2_pp(freeVar, m)
<< " = " << mk_ismt2_pp(dupVar, m) << " (SKIP)" << std::endl;);
continue;
} else {
eqcRepSet.insert(freeVar);
}
}
for (std::set<expr*>::iterator fvIt = eqcRepSet.begin(); fvIt != eqcRepSet.end(); fvIt++) {
bool standAlone = true;
expr * freeVar = *fvIt;
// has length constraint initially
if (input_var_in_len.find(freeVar) != input_var_in_len.end()) {
standAlone = false;
}
// iterate parents
if (standAlone) {
// I hope this works!
enode * e_freeVar = ctx.get_enode(freeVar);
enode_vector::iterator it = e_freeVar->begin_parents();
for (; it != e_freeVar->end_parents(); ++it) {
expr * parentAst = (*it)->get_owner();
if (u.str.is_concat(to_app(parentAst))) {
standAlone = false;
break;
}
}
}
if (standAlone) {
rational len_value;
bool len_value_exists = get_len_value(freeVar, len_value);
if (len_value_exists) {
leafVarSet.insert(freeVar);
} else {
aloneVars[-1].insert(freeVar);
}
} else {
leafVarSet.insert(freeVar);
}
}
for(std::set<expr*>::iterator itor1 = leafVarSet.begin();
itor1 != leafVarSet.end(); ++itor1) {
expr * toAssert = gen_len_val_options_for_free_var(*itor1, NULL, "");
// gen_len_val_options_for_free_var() can legally return NULL,
// as methods that it calls may assert their own axioms instead.
if (toAssert != NULL) {
assert_axiom(toAssert);
}
}
for (std::map<int, std::set<expr*> >::iterator mItor = aloneVars.begin();
mItor != aloneVars.end(); ++mItor) {
std::set<expr*>::iterator itor2 = mItor->second.begin();
for(; itor2 != mItor->second.end(); ++itor2) {
expr * toAssert = gen_len_val_options_for_free_var(*itor2, NULL, "");
// same deal with returning a NULL axiom here
if(toAssert != NULL) {
assert_axiom(toAssert);
}
}
}
}
/*
* Collect all unroll functions
* and constant string in eqc of node n
*/
void theory_str::get_eqc_allUnroll(expr * n, expr * &constStr, std::set<expr*> & unrollFuncSet) {
constStr = NULL;
unrollFuncSet.clear();
expr * curr = n;
do {
if (u.str.is_string(to_app(curr))) {
constStr = curr;
} else if (u.re.is_unroll(to_app(curr))) {
if (unrollFuncSet.find(curr) == unrollFuncSet.end()) {
unrollFuncSet.insert(curr);
}
}
curr = get_eqc_next(curr);
} while (curr != n);
}
// Collect simple Unroll functions (whose core is Str2Reg) and constant strings in the EQC of n.
void theory_str::get_eqc_simpleUnroll(expr * n, expr * &constStr, std::set<expr*> & unrollFuncSet) {
constStr = NULL;
unrollFuncSet.clear();
expr * curr = n;
do {
if (u.str.is_string(to_app(curr))) {
constStr = curr;
} else if (u.re.is_unroll(to_app(curr))) {
expr * core = to_app(curr)->get_arg(0);
if (u.re.is_to_re(to_app(core))) {
if (unrollFuncSet.find(curr) == unrollFuncSet.end()) {
unrollFuncSet.insert(curr);
}
}
}
curr = get_eqc_next(curr);
} while (curr != n);
}
void theory_str::init_model(model_generator & mg) {
//TRACE("str", tout << "initializing model" << std::endl; display(tout););
m_factory = alloc(str_value_factory, get_manager(), get_family_id());
mg.register_factory(m_factory);
}
/*
* Helper function for mk_value().
* Attempts to resolve the expression 'n' to a string constant.
* Stronger than get_eqc_value() in that it will perform recursive descent
* through every subexpression and attempt to resolve those to concrete values as well.
* Returns the concrete value obtained from this process,
* guaranteed to satisfy m_strutil.is_string(),
* if one could be obtained,
* or else returns NULL if no concrete value was derived.
*/
app * theory_str::mk_value_helper(app * n) {
if (u.str.is_string(n)) {
return n;
} else if (u.str.is_concat(n)) {
// recursively call this function on each argument
SASSERT(n->get_num_args() == 2);
expr * a0 = n->get_arg(0);
expr * a1 = n->get_arg(1);
app * a0_conststr = mk_value_helper(to_app(a0));
app * a1_conststr = mk_value_helper(to_app(a1));
if (a0_conststr != NULL && a1_conststr != NULL) {
zstring a0_s, a1_s;
u.str.is_string(a0_conststr, a0_s);
u.str.is_string(a1_conststr, a1_s);
zstring result = a0_s + a1_s;
return to_app(mk_string(result));
}
}
// fallback path
// try to find some constant string, anything, in the equivalence class of n
bool hasEqc = false;
expr * n_eqc = get_eqc_value(n, hasEqc);
if (hasEqc) {
return to_app(n_eqc);
} else {
return NULL;
}
}
model_value_proc * theory_str::mk_value(enode * n, model_generator & mg) {
TRACE("str", tout << "mk_value for: " << mk_ismt2_pp(n->get_owner(), get_manager()) <<
" (sort " << mk_ismt2_pp(get_manager().get_sort(n->get_owner()), get_manager()) << ")" << std::endl;);
ast_manager & m = get_manager();
app_ref owner(m);
owner = n->get_owner();
// If the owner is not internalized, it doesn't have an enode associated.
SASSERT(get_context().e_internalized(owner));
app * val = mk_value_helper(owner);
if (val != NULL) {
return alloc(expr_wrapper_proc, val);
} else {
TRACE("str", tout << "WARNING: failed to find a concrete value, falling back" << std::endl;);
return alloc(expr_wrapper_proc, to_app(mk_string("**UNUSED**")));
}
}
void theory_str::finalize_model(model_generator & mg) {}
void theory_str::display(std::ostream & out) const {
out << "TODO: theory_str display" << std::endl;
}
}; /* namespace smt */
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