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potentially fix out-of-scope infinite loop bug in theory_str gen_unroll_conditional_options

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This commit is contained in:
Murphy Berzish 2016-09-15 15:59:56 -04:00
parent 8776b97841
commit e7c0c29ae5
1 changed files with 42 additions and 15 deletions
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57
src/smt/theory_str.cpp
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@ -504,6 +504,7 @@ app * theory_str::mk_unroll_bound_var() {
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;
}
@ -6595,6 +6596,7 @@ void theory_str::pop_scope_eh(unsigned num_scopes) {
variable_set.erase(*var_it);
internal_variable_set.erase(*var_it);
regex_variable_set.erase(*var_it);
internal_unrollTest_vars.erase(*var_it);
count += 1;
}
TRACE("t_str_detail", tout << "cleaned up " << count << " variables" << std::endl;);
@ -8349,13 +8351,35 @@ expr * theory_str::gen_unroll_conditional_options(expr * var, std::set<expr*> &
litems.push_back(item);
}
// handle out-of-scope entries in unroll_tries_map
ptr_vector<expr> outOfScopeTesters;
// TODO refactor unroll_tries_map and internal_unrollTest_vars to use m_trail_stack
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("t_str_detail", 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++) {
// TODO possibly missing a scope check here
expr * tester = unroll_tries_map[var][unrolls][i];
bool testerHasValue = false;
expr * testerVal = get_eqc_value(tester, testerHasValue);
@ -8377,6 +8401,9 @@ expr * theory_str::gen_unroll_conditional_options(expr * var, std::set<expr*> &
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 {
@ -8881,21 +8908,21 @@ void theory_str::process_free_var(std::map<expr*, int> & freeVar_map) {
* 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();
context & ctx = get_context();
constStr = NULL;
unrollFuncSet.clear();
context & ctx = get_context();
expr * curr = n;
do {
if (is_string(to_app(curr))) {
constStr = curr;
} else if (is_Unroll(to_app(curr))) {
if (unrollFuncSet.find(curr) == unrollFuncSet.end()) {
unrollFuncSet.insert(curr);
}
}
curr = get_eqc_next(curr);
} while (curr != n);
expr * curr = n;
do {
if (is_string(to_app(curr))) {
constStr = curr;
} else if (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.