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successful unroll of simple unbounded Str2Reg

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This commit is contained in:
Murphy Berzish 2016-06-30 02:46:16 -04:00
parent 427632ede3
commit b4110c886f
2 changed files with 126 additions and 2 deletions
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117
src/smt/theory_str.cpp
View file

@ -32,6 +32,7 @@ theory_str::theory_str(ast_manager & m):
opt_AggressiveValueTesting(true),
opt_EagerStringConstantLengthAssertions(true),
opt_VerifyFinalCheckProgress(true),
opt_LCMUnrollStep(2),
/* Internal setup */
search_started(false),
m_autil(m),
@ -458,6 +459,10 @@ app * theory_str::mk_unroll_bound_var() {
return mk_int_var("unroll");
}
app * theory_str::mk_unroll_test_var() {
return mk_str_var("unrollTest"); // was uRt
}
app * theory_str::mk_str_var(std::string name) {
context & ctx = get_context();
ast_manager & m = get_manager();
@ -6093,8 +6098,116 @@ expr * theory_str::gen_assign_unroll_Str2Reg(expr * n, std::set<expr*> & unrolls
}
expr * theory_str::gen_unroll_conditional_options(expr * var, std::set<expr*> & unrolls, std::string lcmStr) {
// TODO NEXT
NOT_IMPLEMENTED_YET();
context & ctx = get_context();
ast_manager & mgr = get_manager();
int dist = opt_LCMUnrollStep;
expr_ref_vector litems(mgr);
expr_ref moreAst(m_strutil.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("t_str_detail", tout << "considering unroll " << mk_pp(item, mgr) << std::endl;);
litems.push_back(item);
}
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];
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("t_str_detail", tout << "lImp = " << mk_pp(lImp, mgr) << std::endl;);
SASSERT(rImp);
TRACE("t_str_detail", tout << "rImp = " << mk_pp(rImp, mgr) << std::endl;);
expr_ref toAssert(mgr.mk_or(mgr.mk_not(lImp), rImp), mgr);
SASSERT(toAssert);
TRACE("t_str_detail", tout << "Making up assignments for variable which is equal to unbounded Unroll" << std::endl;);
m_trail.push_back(toAssert);
return toAssert;
// insert [tester = "more"] to litems so that the implyL for next tester is correct
litems.push_back(ctx.mk_eq_atom(tester, moreAst));
} else {
std::string testerStr = m_strutil.get_string_constant_value(testerVal);
TRACE("t_str_detail", tout << "Tester [" << mk_pp(tester, mgr) << "] = " << testerStr << std::endl;);
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("t_str_detail", 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, std::string lcmStr, expr * testerVar, int l, int h) {
context & ctx = get_context();
ast_manager & mgr = get_manager();
TRACE("t_str_detail", tout << "entry: var = " << mk_pp(var, mgr) << ", lcmStr = " << lcmStr
<< ", l = " << l << ", h = " << h << std::endl;);
expr_ref_vector orItems(mgr);
expr_ref_vector andItems(mgr);
for (int i = l; i < h; i++) {
std::string iStr = int_to_string(i);
expr_ref testerEqAst(ctx.mk_eq_atom(testerVar, m_strutil.mk_string(iStr)), mgr);
TRACE("t_str_detail", tout << "testerEqAst = " << mk_pp(testerEqAst, mgr) << std::endl;);
orItems.push_back(testerEqAst);
std::string unrollStrInstance = get_unrolled_string(lcmStr, i);
expr_ref x1(ctx.mk_eq_atom(testerEqAst, ctx.mk_eq_atom(var, m_strutil.mk_string(unrollStrInstance))), mgr);
TRACE("t_str_detail", 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("t_str_detail", tout << "x2 = " << mk_pp(x2, mgr) << std::endl;);
andItems.push_back(x2);
}
expr_ref testerEqMore(ctx.mk_eq_atom(testerVar, m_strutil.mk_string("more")), mgr);
TRACE("t_str_detail", tout << "testerEqMore = " << mk_pp(testerEqMore, mgr) << std::endl;);
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("t_str_detail", 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("t_str_detail", 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("t_str_detail", 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) {

11
src/smt/theory_str.h
View file

@ -89,6 +89,11 @@ namespace smt {
*/
bool opt_VerifyFinalCheckProgress;
/*
* This constant controls how eagerly we expand unrolls in unbounded regex membership tests.
*/
int opt_LCMUnrollStep;
bool search_started;
arith_util m_autil;
str_util m_strutil;
@ -153,6 +158,10 @@ namespace smt {
std::map<expr*, int_vector> val_range_map;
// This can't be an expr_ref_vector because the constructor is wrong,
// we would need to modify the allocator so we pass in ast_manager
std::map<expr*, std::map<std::set<expr*>, ptr_vector<expr> > > unroll_tries_map;
char * char_set;
std::map<char, int> charSetLookupTable;
int charSetSize;
@ -184,6 +193,7 @@ namespace smt {
expr * mk_internal_valTest_var(expr * node, int len, int vTries);
app * mk_regex_rep_var();
app * mk_unroll_bound_var();
app * mk_unroll_test_var();
bool is_concat(app const * a) const { return a->is_app_of(get_id(), OP_STRCAT); }
bool is_concat(enode const * n) const { return is_concat(n->get_owner()); }
@ -335,6 +345,7 @@ namespace smt {
void gen_assign_unroll_reg(std::set<expr*> & unrolls);
expr * gen_assign_unroll_Str2Reg(expr * n, std::set<expr*> & unrolls);
expr * gen_unroll_conditional_options(expr * var, std::set<expr*> & unrolls, std::string lcmStr);
expr * gen_unroll_assign(expr * var, std::string lcmStr, expr * testerVar, int l, int h);
void dump_assignments();
void initialize_charset();