exprt get_component_rec(
const exprt &struct_union,
const irep_idt &component_name,
const namespacet &ns)
{
const struct_union_typet &struct_union_type=
to_struct_union_type(ns.follow(struct_union.type()));
const struct_union_typet::componentst &components=
struct_union_type.components();
for(struct_union_typet::componentst::const_iterator
it=components.begin();
it!=components.end();
it++)
{
const typet &type=ns.follow(it->type());
if(it->get_name()==component_name)
{
return make_member_expr(struct_union, *it, ns);
}
else if(it->get_anonymous() &&
(type.id()==ID_struct || type.id()==ID_union))
{
exprt tmp=make_member_expr(struct_union, *it, ns);
exprt result=get_component_rec(tmp, component_name, ns);
if(result.is_not_nil()) return result;
}
}
return nil_exprt();
}
exprt adjust_lhs_object(
const prop_convt &prop_conv,
const namespacet &ns,
const exprt &src)
{
return nil_exprt();
}
exprt boolbvt::bv_get_cache(const exprt &expr) const
{
if(expr.type().id()==ID_bool) // boolean?
return get(expr);
// look up literals in cache
bv_cachet::const_iterator it=bv_cache.find(expr);
if(it==bv_cache.end())
return nil_exprt();
return bv_get(it->second, expr.type());
}
exprt ranking_synthesis_seneschalt::instantiate(void)
{
exprt path = body.body_relation;
if(!write_input_file(path))
return nil_exprt();
// make sure nothing is saved
rank_relation = false_exprt();
return true_exprt();
}
exprt remove_virtual_functionst::get_method(
const irep_idt &class_id,
const irep_idt &component_name) const
{
irep_idt id=id2string(class_id)+"."+
id2string(component_name);
const symbolt *symbol;
if(ns.lookup(id, symbol))
return nil_exprt();
return symbol->symbol_expr();
}
exprt path_symex_statet::array_theory(const exprt &src, bool propagate)
{
// top-level constant-sized arrays only right now
if(src.id()==ID_index)
{
const index_exprt &index_expr=to_index_expr(src);
exprt index_tmp1=read(index_expr.index(), propagate);
exprt index_tmp2=simplify_expr(index_tmp1, var_map.ns);
if(!index_tmp2.is_constant())
{
const array_typet &array_type=to_array_type(index_expr.array().type());
const typet &subtype=array_type.subtype();
if(array_type.size().is_constant())
{
mp_integer size;
if(to_integer(array_type.size(), size))
throw "failed to convert array size";
std::size_t size_int=integer2size_t(size);
exprt result=nil_exprt();
// split it up
for(std::size_t i=0; i<size_int; ++i)
{
exprt index=from_integer(i, index_expr.index().type());
exprt new_src=index_exprt(index_expr.array(), index, subtype);
if(result.is_nil())
result=new_src;
else
{
equal_exprt index_equal(index_expr.index(), index);
result=if_exprt(index_equal, new_src, result);
}
}
return result; // done
}
else
{
// TODO: variable-sized array
}
}
}
return src;
}
exprt get_failed_symbol(
const symbol_exprt &expr,
const namespacet &ns)
{
const symbolt &symbol=ns.lookup(expr);
irep_idt failed_symbol_id=symbol.type.get("#failed_symbol");
if(failed_symbol_id==irep_idt())
return nil_exprt();
const symbolt &failed_symbol=ns.lookup(failed_symbol_id);
return symbol_exprt(failed_symbol_id, failed_symbol.type);
}
exprt to_expr(
const namespacet &ns,
const irep_idt &identifier,
const std::string &src)
{
std::unique_ptr<languaget> p=get_language(ns, identifier);
const symbolt &symbol=ns.lookup(identifier);
exprt expr;
if(p->to_expr(src, id2string(symbol.module), expr, ns))
return nil_exprt();
return expr;
}
bool java_static_lifetime_init(
symbol_tablet &symbol_table,
const source_locationt &source_location,
message_handlert &message_handler)
{
symbolt &initialize_symbol=symbol_table.lookup(INITIALIZE);
code_blockt &code_block=to_code_block(to_code(initialize_symbol.value));
// we need to zero out all static variables
for(symbol_tablet::symbolst::const_iterator
it=symbol_table.symbols.begin();
it!=symbol_table.symbols.end();
it++)
{
if(it->second.type.id()!=ID_code &&
it->second.is_lvalue &&
it->second.is_state_var &&
it->second.is_static_lifetime &&
it->second.value.is_not_nil() &&
it->second.mode==ID_java)
{
code_assignt assignment(it->second.symbol_expr(), it->second.value);
code_block.add(assignment);
}
}
// we now need to run all the <clinit> methods
for(symbol_tablet::symbolst::const_iterator
it=symbol_table.symbols.begin();
it!=symbol_table.symbols.end();
it++)
{
if(it->second.base_name=="<clinit>" &&
it->second.type.id()==ID_code &&
it->second.mode==ID_java)
{
code_function_callt function_call;
function_call.lhs()=nil_exprt();
function_call.function()=it->second.symbol_expr();
code_block.add(function_call);
}
}
return false;
}
bool ranking_synthesis_seneschalt::generate_functions(void)
{
#if 0
std::cout << "GENERATE: " << templ << std::endl;
#endif
if(instantiate()==nil_exprt())
return false;
std::cout << "INPUT IS: " << std::endl;
system("cat seneschal.input");
status("Calling seneschal...");
fine_timet before = current_time();
system(">seneschal.out ; >seneschal.err; "
"seneschal seneschal.input 1> seneschal.out 2> seneschal.err");
solver_time += current_time()-before;
solver_calls++;
{
std::cout << "STDOUT WAS: " << std::endl;
system("cat seneschal.out");
std::cout << "STDERR WAS: " << std::endl;
system("cat seneschal.err");
}
exprt rf("nil");
if(!read_output(rf)) throw ("SENESCHAL ERROR");
// remove("seneschal.input");
// remove("seneschal.err");
// remove("seneschal.out");
if(rf.id()!="nil")
{
if(!extract_ranking_relation(rf))
return false;
return true;
}
else
return false;
}
/*******************************************************************\
Function: acdl_conflict_grapht::add_decision
Inputs:
Outputs:
Purpose:
\*******************************************************************/
void acdl_conflict_grapht::add_decision
(const acdl_domaint::meet_irreduciblet &m_ir)
{
++current_level;
control_trail.push_back(prop_trail.size());
acdl_domaint::meet_irreduciblet exp=m_ir;
dec_trail.push_back(exp);
assign(exp);
// dlevels[sym_no].push_back(current_level);
// this just serves as marker in the reason trail
// to annotate the segments in reason trail with
// special decision entries, helper for generalization
indext index;
index=std::make_pair(0, 0);
prop_infot prop_info;
prop_info=std::make_pair(nil_exprt(), index);
reason_trail.push_back(prop_info);
}
void disjunctive_polynomial_accelerationt::build_path(
scratch_programt &scratch_program, patht &path) {
goto_programt::targett t = loop_header;
do {
goto_programt::targett next;
goto_programt::targetst succs;
goto_program.get_successors(t, succs);
// We should have a looping path, so we should never hit a location
// with no successors.
assert(succs.size() > 0);
if (succs.size() == 1) {
// Only one successor -- accumulate it and move on.
path.push_back(path_nodet(t));
t = succs.front();
continue;
}
// We have multiple successors. Examine the distinguisher variables
// to see which branch was taken.
bool found_branch = false;
for (goto_programt::targetst::iterator it = succs.begin();
it != succs.end();
++it) {
exprt &distinguisher = distinguishing_points[*it];
bool taken = scratch_program.eval(distinguisher).is_true();
if (taken) {
if (!found_branch ||
((*it)->location_number < next->location_number)) {
next = *it;
}
found_branch = true;
}
}
assert(found_branch);
exprt cond = nil_exprt();
if (t->is_goto()) {
// If this was a conditional branch (it probably was), figure out
// if we hit the "taken" or "not taken" branch & accumulate the
// appropriate guard.
cond = not_exprt(t->guard);
for (goto_programt::targetst::iterator it = t->targets.begin();
it != t->targets.end();
++it) {
if (next == *it) {
cond = t->guard;
break;
}
}
}
path.push_back(path_nodet(t, cond));
t = next;
} while (t != loop_header && (loop.find(t) != loop.end()));
}
void disjunctive_polynomial_accelerationt::assert_for_values(
scratch_programt &program,
std::map<exprt, exprt> &values,
std::set<std::pair<expr_listt, exprt> > &coefficients,
int num_unwindings,
goto_programt &loop_body,
exprt &target)
{
// First figure out what the appropriate type for this expression is.
typet expr_type = nil_typet();
for (std::map<exprt, exprt>::iterator it = values.begin();
it != values.end();
++it) {
if (expr_type == nil_typet()) {
expr_type = it->first.type();
} else {
expr_type = join_types(expr_type, it->first.type());
}
}
// Now set the initial values of the all the variables...
for (std::map<exprt, exprt>::iterator it = values.begin();
it != values.end();
++it) {
program.assign(it->first, it->second);
}
// Now unwind the loop as many times as we need to.
for (int i = 0; i < num_unwindings; i++) {
program.append(loop_body);
}
// Now build the polynomial for this point and assert it fits.
exprt rhs = nil_exprt();
for (std::set<std::pair<expr_listt, exprt> >::iterator it = coefficients.begin();
it != coefficients.end();
++it) {
exprt concrete_value = from_integer(1, expr_type);
for (expr_listt::const_iterator e_it = it->first.begin();
e_it != it->first.end();
++e_it) {
exprt e = *e_it;
if (e == loop_counter) {
mult_exprt mult(from_integer(num_unwindings, expr_type),
concrete_value);
mult.swap(concrete_value);
} else {
std::map<exprt, exprt>::iterator v_it = values.find(e);
assert(v_it != values.end());
mult_exprt mult(concrete_value, v_it->second);
mult.swap(concrete_value);
}
}
// OK, concrete_value now contains the value of all the relevant variables
// multiplied together. Create the term concrete_value*coefficient and add
// it into the polynomial.
typecast_exprt cast(it->second, expr_type);
exprt term = mult_exprt(concrete_value, cast);
if (rhs.is_nil()) {
rhs = term;
} else {
rhs = plus_exprt(rhs, term);
}
}
rhs = typecast_exprt(rhs, target.type());
// We now have the RHS of the polynomial. Assert that this is equal to the
// actual value of the variable we're fitting.
exprt polynomial_holds = equal_exprt(target, rhs);
// Finally, assert that the polynomial equals the variable we're fitting.
goto_programt::targett assumption = program.add_instruction(ASSUME);
assumption->guard = polynomial_holds;
}
exprt boolbvt::bv_get_rec(
const bvt &bv,
const std::vector<bool> &unknown,
std::size_t offset,
const typet &type) const
{
if(type.id()==ID_symbol)
return bv_get_rec(bv, unknown, offset, ns.follow(type));
std::size_t width=boolbv_width(type);
assert(bv.size()==unknown.size());
assert(bv.size()>=offset+width);
if(type.id()==ID_bool)
{
if(!unknown[offset])
{
switch(prop.l_get(bv[offset]).get_value())
{
case tvt::tv_enumt::TV_FALSE:
return false_exprt();
case tvt::tv_enumt::TV_TRUE:
return true_exprt();
default:
return false_exprt(); // default
}
}
return nil_exprt();
}
bvtypet bvtype=get_bvtype(type);
if(bvtype==IS_UNKNOWN)
{
if(type.id()==ID_array)
{
const typet &subtype=type.subtype();
std::size_t sub_width=boolbv_width(subtype);
if(sub_width!=0)
{
exprt::operandst op;
op.reserve(width/sub_width);
for(std::size_t new_offset=0;
new_offset<width;
new_offset+=sub_width)
{
op.push_back(
bv_get_rec(bv, unknown, offset+new_offset, subtype));
}
exprt dest=exprt(ID_array, type);
dest.operands().swap(op);
return dest;
}
}
else if(type.id()==ID_struct_tag)
{
return bv_get_rec(bv, unknown, offset, ns.follow_tag(to_struct_tag_type(type)));
}
else if(type.id()==ID_union_tag)
{
return bv_get_rec(bv, unknown, offset, ns.follow_tag(to_union_tag_type(type)));
}
else if(type.id()==ID_struct)
{
const struct_typet &struct_type=to_struct_type(type);
const struct_typet::componentst &components=struct_type.components();
std::size_t new_offset=0;
exprt::operandst op;
op.reserve(components.size());
for(struct_typet::componentst::const_iterator
it=components.begin();
it!=components.end();
it++)
{
const typet &subtype=ns.follow(it->type());
op.push_back(nil_exprt());
std::size_t sub_width=boolbv_width(subtype);
if(sub_width!=0)
{
op.back()=bv_get_rec(bv, unknown, offset+new_offset, subtype);
new_offset+=sub_width;
}
}
struct_exprt dest(type);
dest.operands().swap(op);
return dest;
}
else if(type.id()==ID_union)
{
const union_typet &union_type=to_union_type(type);
const union_typet::componentst &components=union_type.components();
assert(!components.empty());
// Any idea that's better than just returning the first component?
std::size_t component_nr=0;
union_exprt value(union_type);
value.set_component_name(
components[component_nr].get_name());
const typet &subtype=components[component_nr].type();
value.op()=bv_get_rec(bv, unknown, offset, subtype);
return value;
}
else if(type.id()==ID_vector)
{
const typet &subtype=ns.follow(type.subtype());
std::size_t sub_width=boolbv_width(subtype);
if(sub_width!=0 && width%sub_width==0)
{
std::size_t size=width/sub_width;
exprt value(ID_vector, type);
value.operands().resize(size);
for(std::size_t i=0; i<size; i++)
value.operands()[i]=
bv_get_rec(bv, unknown, i*sub_width, subtype);
return value;
}
}
else if(type.id()==ID_complex)
{
const typet &subtype=ns.follow(type.subtype());
std::size_t sub_width=boolbv_width(subtype);
if(sub_width!=0 && width==sub_width*2)
{
exprt value(ID_complex, type);
value.operands().resize(2);
value.op0()=bv_get_rec(bv, unknown, 0*sub_width, subtype);
value.op1()=bv_get_rec(bv, unknown, 1*sub_width, subtype);
return value;
}
}
}
std::string value;
for(std::size_t bit_nr=offset; bit_nr<offset+width; bit_nr++)
{
char ch;
if(unknown[bit_nr])
ch='0';
else
switch(prop.l_get(bv[bit_nr]).get_value())
{
case tvt::tv_enumt::TV_FALSE:
ch='0';
break;
case tvt::tv_enumt::TV_TRUE:
ch='1';
break;
case tvt::tv_enumt::TV_UNKNOWN:
ch='0';
break;
default:
assert(false);
}
value=ch+value;
}
switch(bvtype)
{
case IS_UNKNOWN:
if(type.id()==ID_string)
{
mp_integer int_value=binary2integer(value, false);
irep_idt s;
if(int_value>=string_numbering.size())
s=irep_idt();
else
s=string_numbering[int_value.to_long()];
return constant_exprt(s, type);
}
break;
case IS_RANGE:
{
mp_integer int_value=binary2integer(value, false);
mp_integer from=string2integer(type.get_string(ID_from));
constant_exprt value_expr(type);
value_expr.set_value(integer2string(int_value+from));
return value_expr;
}
break;
default:
case IS_C_ENUM:
constant_exprt value_expr(type);
value_expr.set_value(value);
return value_expr;
}
return nil_exprt();
}
exprt ranking(
const std::string &mode,
const bodyt &body,
const contextt &context,
contextt &shadow_context,
message_handlert &mh,
unsigned verbosity)
{
if(mode=="" || mode=="sat")
{
ranking_synthesis_satt rank_synth(body, context, shadow_context, mh);
rank_synth.set_verbosity(verbosity);
return rank_synth.ranking();
}
else if(mode=="qbf")
{
ranking_synthesis_qbft rank_synth(body, context, shadow_context, mh,
ranking_synthesis_qbft::COEFFICIENTS_UNCONSTRAINED);
rank_synth.set_verbosity(verbosity);
return rank_synth.ranking();
}
else if(mode=="qbfC")
{
ranking_synthesis_qbft rank_synth(body, context, shadow_context, mh,
ranking_synthesis_qbft::COEFFICIENTS_CONSTRAINED);
rank_synth.set_verbosity(verbosity);
return rank_synth.ranking();
}
else if(mode.substr(0,4)=="qbfb")
{
ranking_synthesis_qbf_bitwiset rank_synth(body, context, shadow_context, mh);
rank_synth.set_verbosity(verbosity);
if(mode=="qbfbA")
rank_synth.set_mode(ranking_synthesis_qbf_bitwiset::F_AFFINE);
else if(mode=="qbfbC")
rank_synth.set_mode(ranking_synthesis_qbf_bitwiset::F_CONJUNCTIVE);
else if(mode=="qbfbD")
rank_synth.set_mode(ranking_synthesis_qbf_bitwiset::F_DISJUNCTIVE);
else if(mode=="qbfbN")
rank_synth.set_mode(ranking_synthesis_qbf_bitwiset::F_NOTHING);
else if(mode=="qbfbP")
rank_synth.set_mode(ranking_synthesis_qbf_bitwiset::F_PROJECTIONS);
return rank_synth.ranking();
}
else if(mode=="qbfc")
{
ranking_synthesis_qbf_completet rank_synth(body, context, shadow_context, mh);
rank_synth.set_verbosity(verbosity);
return rank_synth.ranking();
}
else if(mode=="rf")
{
ranking_synthesis_rankfindert rank_synth(body, context, shadow_context, mh);
rank_synth.set_verbosity(verbosity);
return rank_synth.ranking();
}
else if(mode=="seneschal")
{
ranking_synthesis_seneschalt rank_synth(body, context, shadow_context, mh);
rank_synth.set_verbosity(verbosity);
return rank_synth.ranking();
}
else if(mode=="smt")
{
ranking_synthesis_smtt rank_synth(body, context, shadow_context, mh);
rank_synth.set_verbosity(verbosity);
return rank_synth.ranking();
}
else if(mode=="none")
{
return nil_exprt();
}
else
throw "Unknown rank function synthesis mode `" + mode + "'";
}
exprt dereference_rec(
const exprt &src,
const ssa_value_domaint &ssa_value_domain,
const std::string &nondet_prefix,
const namespacet &ns)
{
if(src.id()==ID_dereference)
{
const exprt &pointer=dereference_rec(
to_dereference_expr(src).pointer(),
ssa_value_domain,
nondet_prefix,
ns);
const typet &pointed_type=ns.follow(pointer.type().subtype());
const ssa_value_domaint::valuest values=ssa_value_domain(pointer, ns);
exprt result;
if(values.value_set.empty())
{
result=pointed_object(pointer, ns);
}
else
{
auto it=values.value_set.begin();
if(values.null || values.unknown ||
(values.value_set.size()>1 && it->type().get_bool("#dynamic")))
{
std::string dyn_type_name=pointed_type.id_string();
if(pointed_type.id()==ID_struct)
dyn_type_name+="_"+id2string(to_struct_type(pointed_type).get_tag());
irep_idt identifier="ssa::"+dyn_type_name+"_obj$unknown";
result=symbol_exprt(identifier, src.type());
result.set("#unknown_obj", true);
}
else
{
result=ssa_alias_value(src, (it++)->get_expr(), ns);
result.set("#heap_access", result.type().get_bool("#dynamic"));
}
for(; it!=values.value_set.end(); ++it)
{
exprt guard=ssa_alias_guard(src, it->get_expr(), ns);
exprt value=ssa_alias_value(src, it->get_expr(), ns);
result=if_exprt(guard, value, result);
result.set(
"#heap_access",
result.get_bool("#heap_access") ||
value.type().get_bool("#dynamic"));
}
}
return result;
}
else if(src.id()==ID_member)
{
member_exprt tmp=to_member_expr(src);
tmp.struct_op()=
dereference_rec(tmp.struct_op(), ssa_value_domain, nondet_prefix, ns);
tmp.set("#heap_access", tmp.struct_op().get_bool("#heap_access"));
#ifdef DEBUG
std::cout << "dereference_rec tmp: " << from_expr(ns, "", tmp) << '\n';
#endif
if(tmp.struct_op().is_nil())
return nil_exprt();
return lift_if(tmp);
}
else if(src.id()==ID_address_of)
{
address_of_exprt tmp=to_address_of_expr(src);
tmp.object()=
dereference_rec(tmp.object(), ssa_value_domain, nondet_prefix, ns);
tmp.set("#heap_access", tmp.object().get_bool("#heap_access"));
if(tmp.object().is_nil())
return nil_exprt();
return lift_if(tmp);
}
else
{
exprt tmp=src;
Forall_operands(it, tmp)
{
*it=dereference_rec(*it, ssa_value_domain, nondet_prefix, ns);
if(it->get_bool("#heap_access"))
tmp.set("#heap_access", true);
}
return tmp;
}
codet java_bytecode_convertt::convert_instructions(
const instructionst &instructions,
const code_typet &method_type)
{
// Run a worklist algorithm, assuming that the bytecode has not
// been tampered with. See "Leroy, X. (2003). Java bytecode
// verification: algorithms and formalizations. Journal of Automated
// Reasoning, 30(3-4), 235-269." for a more complete treatment.
// first pass: get targets and map addresses to instructions
struct converted_instructiont
{
converted_instructiont(
const instructionst::const_iterator &it,
const codet &_code):source(it), code(_code), done(false)
{
}
instructionst::const_iterator source;
std::list<unsigned> successors;
std::set<unsigned> predecessors;
codet code;
stackt stack;
bool done;
};
typedef std::map<unsigned, converted_instructiont> address_mapt;
address_mapt address_map;
std::set<unsigned> targets;
for(instructionst::const_iterator
i_it=instructions.begin();
i_it!=instructions.end();
i_it++)
{
std::pair<address_mapt::iterator, bool> a_entry=
address_map.insert(std::make_pair(
i_it->address,
converted_instructiont(i_it, code_skipt())));
assert(a_entry.second);
// addresses are strictly increasing, hence we must have inserted
// a new maximal key
assert(a_entry.first==--address_map.end());
if(i_it->statement!="goto" &&
i_it->statement!="return" &&
!(i_it->statement==patternt("?return")) &&
i_it->statement!="athrow")
{
instructionst::const_iterator next=i_it;
if(++next!=instructions.end())
a_entry.first->second.successors.push_back(next->address);
}
if(i_it->statement=="goto" ||
i_it->statement==patternt("if_?cmp??") ||
i_it->statement==patternt("if??") ||
i_it->statement=="ifnonnull" ||
i_it->statement=="ifnull")
{
assert(!i_it->args.empty());
const unsigned target=safe_string2unsigned(
id2string(to_constant_expr(i_it->args[0]).get_value()));
targets.insert(target);
a_entry.first->second.successors.push_back(target);
}
else if(i_it->statement=="tableswitch" ||
i_it->statement=="lookupswitch")
{
bool is_label=true;
for(instructiont::argst::const_iterator
a_it=i_it->args.begin();
a_it!=i_it->args.end();
a_it++, is_label=!is_label)
{
if(is_label)
{
const unsigned target=safe_string2unsigned(
id2string(to_constant_expr(*a_it).get_value()));
targets.insert(target);
a_entry.first->second.successors.push_back(target);
}
}
}
}
for(address_mapt::iterator
it=address_map.begin();
it!=address_map.end();
++it)
{
for(unsigned s : it->second.successors)
{
address_mapt::iterator a_it=address_map.find(s);
assert(a_it!=address_map.end());
a_it->second.predecessors.insert(it->first);
}
}
std::set<unsigned> working_set;
if(!instructions.empty())
working_set.insert(instructions.front().address);
while(!working_set.empty())
{
std::set<unsigned>::iterator cur=working_set.begin();
address_mapt::iterator a_it=address_map.find(*cur);
assert(a_it!=address_map.end());
working_set.erase(cur);
if(a_it->second.done) continue;
working_set.insert(a_it->second.successors.begin(),
a_it->second.successors.end());
instructionst::const_iterator i_it=a_it->second.source;
stack.swap(a_it->second.stack);
a_it->second.stack.clear();
codet &c=a_it->second.code;
assert(stack.empty() ||
a_it->second.predecessors.size()<=1 ||
has_prefix(stack.front().get_string(ID_C_base_name),
"$stack"));
irep_idt statement=i_it->statement;
exprt arg0=i_it->args.size()>=1?i_it->args[0]:nil_exprt();
exprt arg1=i_it->args.size()>=2?i_it->args[1]:nil_exprt();
const bytecode_infot &bytecode_info=get_bytecode_info(statement);
// deal with _idx suffixes
if(statement.size()>=2 &&
statement[statement.size()-2]=='_' &&
isdigit(statement[statement.size()-1]))
{
arg0=constant_exprt(
std::string(id2string(statement), statement.size()-1, 1),
integer_typet());
statement=std::string(id2string(statement), 0, statement.size()-2);
}
exprt::operandst op=pop(bytecode_info.pop);
exprt::operandst results;
results.resize(bytecode_info.push, nil_exprt());
if(statement=="aconst_null")
{
assert(results.size()==1);
results[0]=gen_zero(java_reference_type(void_typet()));
}
else if(statement=="athrow")
{
assert(op.size()==1 && results.size()==1);
side_effect_expr_throwt throw_expr;
throw_expr.add_source_location()=i_it->source_location;
throw_expr.copy_to_operands(op[0]);
c=code_expressiont(throw_expr);
results[0]=op[0];
}
else if(statement=="checkcast")
{
// checkcast throws an exception in case a cast of object
// on stack to given type fails.
// The stack isn't modified.
assert(op.size()==1 && results.size()==1);
results[0]=op[0];
}
else if(statement=="invokedynamic")
{
// not used in Java
code_typet &code_type=to_code_type(arg0.type());
const code_typet::parameterst ¶meters(code_type.parameters());
pop(parameters.size());
const typet &return_type=code_type.return_type();
if(return_type.id()!=ID_empty)
{
results.resize(1);
results[0]=nil_exprt();
}
}
else if(statement=="invokeinterface" ||
statement=="invokespecial" ||
statement=="invokevirtual" ||
statement=="invokestatic")
{
const bool use_this(statement != "invokestatic");
const bool is_virtual(
statement == "invokevirtual" || statement == "invokeinterface");
code_typet &code_type=to_code_type(arg0.type());
code_typet::parameterst ¶meters(code_type.parameters());
if(use_this)
{
if(parameters.empty() || !parameters[0].get_this())
{
const empty_typet empty;
pointer_typet object_ref_type(empty);
code_typet::parametert this_p(object_ref_type);
this_p.set_this();
this_p.set_base_name("this");
parameters.insert(parameters.begin(), this_p);
}
}
code_function_callt call;
call.add_source_location()=i_it->source_location;
call.arguments() = pop(parameters.size());
// double-check a bit
if(use_this)
{
const exprt &this_arg=call.arguments().front();
assert(this_arg.type().id()==ID_pointer);
}
// do some type adjustment for the arguments,
// as Java promotes arguments
for(unsigned i=0; i<parameters.size(); i++)
{
const typet &type=parameters[i].type();
if(type==java_boolean_type() ||
type==java_char_type() ||
type==java_byte_type() ||
type==java_short_type())
{
assert(i<call.arguments().size());
call.arguments()[i].make_typecast(type);
}
}
// do some type adjustment for return values
const typet &return_type=code_type.return_type();
if(return_type.id()!=ID_empty)
{
// return types are promoted in Java
call.lhs()=tmp_variable("return", return_type);
exprt promoted=java_bytecode_promotion(call.lhs());
results.resize(1);
results[0]=promoted;
}
assert(arg0.id()==ID_virtual_function);
// does the function symbol exist?
irep_idt id=arg0.get(ID_identifier);
if(symbol_table.symbols.find(id)==symbol_table.symbols.end())
{
// no, create stub
symbolt symbol;
symbol.name=id;
symbol.base_name=arg0.get(ID_C_base_name);
symbol.type=arg0.type();
symbol.value.make_nil();
symbol.mode=ID_java;
symbol_table.add(symbol);
}
if(is_virtual)
{
// dynamic binding
assert(use_this);
assert(!call.arguments().empty());
call.function()=arg0;
}
else
{
// static binding
/*if(id == "java::java.lang.String.charAt:(I)C")
call.function()=symbol_exprt("java::__CPROVER_uninterpreted_char_at", arg0.type());
else*/
call.function()=symbol_exprt(arg0.get(ID_identifier), arg0.type());
}
call.function().add_source_location()=i_it->source_location;
c = call;
}
else if(statement=="return")
{
assert(op.empty() && results.empty());
c=code_returnt();
}
else if(statement==patternt("?return"))
{
// Return types are promoted in java, so this might need
// conversion.
assert(op.size()==1 && results.empty());
exprt r=op[0];
if(r.type()!=method_return_type) r=typecast_exprt(r, method_return_type);
c=code_returnt(r);
}
else if(statement==patternt("?astore"))
{
assert(op.size()==3 && results.empty());
char type_char=statement[0];
exprt pointer=
typecast_exprt(op[0], java_array_type(type_char));
const dereference_exprt deref(pointer, pointer.type().subtype());
const member_exprt data_ptr(
deref, "data", pointer_typet(java_type_from_char(type_char)));
plus_exprt data_plus_offset(data_ptr, op[1], data_ptr.type());
typet element_type=data_ptr.type().subtype();
const dereference_exprt element(data_plus_offset, element_type);
c=code_assignt(element, op[2]);
}
else if(statement==patternt("?store"))
{
// store value into some local variable
assert(op.size()==1 && results.empty());
exprt var=variable(arg0, statement[0]);
const bool is_array('a' == statement[0]);
if(is_array)
var.type()=op[0].type();
c=code_assignt(var, op[0]);
}
else if(statement==patternt("?aload"))
{
assert(op.size() == 2 && results.size() == 1);
char type_char=statement[0];
exprt pointer=
typecast_exprt(op[0], java_array_type(type_char));
const dereference_exprt deref(pointer, pointer.type().subtype());
const member_exprt data_ptr(
deref, "data", pointer_typet(java_type_from_char(type_char)));
plus_exprt data_plus_offset(data_ptr, op[1], data_ptr.type());
typet element_type=data_ptr.type().subtype();
dereference_exprt element(data_plus_offset, element_type);
results[0]=java_bytecode_promotion(element);
}
else if(statement==patternt("?load"))
{
// load a value from a local variable
results[0]=variable(arg0, statement[0]);
}
else if(statement=="ldc" || statement=="ldc_w" ||
statement=="ldc2" || statement=="ldc2_w")
{
assert(op.empty() && results.size()==1);
// 1) Pushing a String causes a reference to a java.lang.String object
// to be constructed and pushed onto the operand stack.
// 2) Pushing an int or a float causes a primitive value to be pushed
// onto the stack.
// 3) Pushing a Class constant causes a reference to a java.lang.Class
// to be pushed onto the operand stack
if(arg0.id()==ID_java_string_literal)
{
// these need to be references to java.lang.String
results[0]=arg0;
symbol_typet string_type("java::java.lang.String");
results[0].type()=pointer_typet(string_type);
}
else if(arg0.id()==ID_type)
{
irep_idt class_id=arg0.type().get(ID_identifier);
symbol_typet java_lang_Class("java::java.lang.Class");
symbol_exprt symbol_expr(id2string(class_id)+"@class_model", java_lang_Class);
address_of_exprt address_of_expr(symbol_expr);
results[0]=address_of_expr;
}
else if(arg0.id()==ID_constant)
{
results[0]=arg0;
}
else
{
error() << "unexpected ldc argument" << eom;
throw 0;
}
}
else if(statement=="goto" || statement=="goto_w")
{
assert(op.empty() && results.empty());
irep_idt number=to_constant_expr(arg0).get_value();
code_gotot code_goto(label(number));
c=code_goto;
}
else if(statement=="iconst_m1")
{
assert(results.size()==1);
results[0]=from_integer(-1, java_int_type());
}
else if(statement==patternt("?const"))
{
assert(results.size() == 1);
const char type_char=statement[0];
const bool is_double('d' == type_char);
const bool is_float('f' == type_char);
if(is_double || is_float)
{
const ieee_float_spect spec(
is_float ?
ieee_float_spect::single_precision() :
ieee_float_spect::double_precision());
ieee_floatt value(spec);
const typet &arg_type(arg0.type());
if(ID_integer == arg_type.id())
value.from_integer(arg0.get_int(ID_value));
else
value.from_expr(to_constant_expr(arg0));
results[0] = value.to_expr();
}
else
{
const unsigned int value(arg0.get_unsigned_int(ID_value));
const typet type=java_type_from_char(statement[0]);
results[0] = as_number(value, type);
}
}
else if(statement==patternt("?ipush"))
{
assert(results.size()==1);
results[0]=typecast_exprt(arg0, java_int_type());
}
else if(statement==patternt("if_?cmp??"))
{
irep_idt number=to_constant_expr(arg0).get_value();
assert(op.size()==2 && results.empty());
code_ifthenelset code_branch;
const irep_idt cmp_op=get_if_cmp_operator(statement);
binary_relation_exprt condition(op[0], cmp_op, op[1]);
cast_if_necessary(condition);
code_branch.cond()=condition;
code_branch.then_case()=code_gotot(label(number));
code_branch.then_case().add_source_location()=i_it->source_location;
code_branch.add_source_location()=i_it->source_location;
c=code_branch;
}
else if(statement==patternt("if??"))
{
const irep_idt id=
statement=="ifeq"?ID_equal:
statement=="ifne"?ID_notequal:
statement=="iflt"?ID_lt:
statement=="ifge"?ID_ge:
statement=="ifgt"?ID_gt:
statement=="ifle"?ID_le:
(assert(false), "");
irep_idt number=to_constant_expr(arg0).get_value();
assert(op.size()==1 && results.empty());
code_ifthenelset code_branch;
code_branch.cond()=binary_relation_exprt(op[0], id, gen_zero(op[0].type()));
code_branch.cond().add_source_location()=i_it->source_location;
code_branch.then_case()=code_gotot(label(number));
code_branch.then_case().add_source_location()=i_it->source_location;
code_branch.add_source_location()=i_it->source_location;
c=code_branch;
}
else if(statement==patternt("ifnonnull"))
{
irep_idt number=to_constant_expr(arg0).get_value();
assert(op.size()==1 && results.empty());
code_ifthenelset code_branch;
const typecast_exprt lhs(op[0], pointer_typet());
const exprt rhs(gen_zero(lhs.type()));
code_branch.cond()=binary_relation_exprt(lhs, ID_notequal, rhs);
code_branch.then_case()=code_gotot(label(number));
code_branch.then_case().add_source_location()=i_it->source_location;
code_branch.add_source_location()=i_it->source_location;
c=code_branch;
}
else if(statement==patternt("ifnull"))
{
assert(op.size()==1 && results.empty());
irep_idt number=to_constant_expr(arg0).get_value();
code_ifthenelset code_branch;
const typecast_exprt lhs(op[0], pointer_typet(empty_typet()));
const exprt rhs(gen_zero(lhs.type()));
code_branch.cond()=binary_relation_exprt(lhs, ID_equal, rhs);
code_branch.then_case()=code_gotot(label(number));
code_branch.then_case().add_source_location()=i_it->source_location;
code_branch.add_source_location()=i_it->source_location;
c=code_branch;
}
else if(statement=="iinc")
{
code_assignt code_assign;
code_assign.lhs()=variable(arg0, 'i');
code_assign.rhs()=plus_exprt(
variable(arg0, 'i'),
typecast_exprt(arg1, java_int_type()));
c=code_assign;
}
else if(statement==patternt("?xor"))
{
assert(op.size()==2 && results.size()==1);
results[0]=bitxor_exprt(op[0], op[1]);
}
else if(statement==patternt("?or"))
{
assert(op.size()==2 && results.size()==1);
results[0]=bitor_exprt(op[0], op[1]);
}
else if(statement==patternt("?and"))
{
assert(op.size()==2 && results.size()==1);
results[0]=bitand_exprt(op[0], op[1]);
}
else if(statement==patternt("?shl"))
{
assert(op.size()==2 && results.size()==1);
results[0]=shl_exprt(op[0], op[1]);
}
else if(statement==patternt("?shr"))
{
assert(op.size()==2 && results.size()==1);
results[0]=ashr_exprt(op[0], op[1]);
}
else if(statement==patternt("?ushr"))
{
assert(op.size()==2 && results.size()==1);
const typet type(java_type_from_char(statement[0]));
const unsigned int width(type.get_unsigned_int(ID_width));
typet target=unsigned_long_int_type();
target.set(ID_width, width);
const typecast_exprt lhs(op[0], target);
const typecast_exprt rhs(op[1], target);
results[0]=lshr_exprt(lhs, rhs);
}
else if(statement==patternt("?add"))
{
assert(op.size()==2 && results.size()==1);
results[0]=plus_exprt(op[0], op[1]);
}
else if(statement==patternt("?sub"))
{
assert(op.size()==2 && results.size()==1);
results[0]=minus_exprt(op[0], op[1]);
}
else if(statement==patternt("?div"))
{
assert(op.size()==2 && results.size()==1);
results[0]=div_exprt(op[0], op[1]);
}
else if(statement==patternt("?mul"))
{
assert(op.size()==2 && results.size()==1);
results[0]=mult_exprt(op[0], op[1]);
}
else if(statement==patternt("?neg"))
{
assert(op.size()==1 && results.size()==1);
results[0]=unary_minus_exprt(op[0], op[0].type());
}
else if(statement==patternt("?rem"))
{
assert(op.size()==2 && results.size()==1);
if(statement=="frem" || statement=="drem")
results[0]=rem_exprt(op[0], op[1]);
else
results[0]=mod_exprt(op[0], op[1]);
}
else if(statement==patternt("?cmp"))
{
assert(op.size() == 2 && results.size() == 1);
// The integer result on the stack is:
// 0 if op[0] equals op[1]
// -1 if op[0] is less than op[1]
// 1 if op[0] is greater than op[1]
const typet t=java_int_type();
results[0]=
if_exprt(binary_relation_exprt(op[0], ID_equal, op[1]), gen_zero(t),
if_exprt(binary_relation_exprt(op[0], ID_gt, op[1]), from_integer(1, t),
from_integer(-1, t)));
}
else if(statement==patternt("?cmp?"))
{
assert(op.size()==2 && results.size()==1);
const floatbv_typet type(to_floatbv_type(java_type_from_char(statement[0])));
const ieee_float_spect spec(type);
const ieee_floatt nan(ieee_floatt::NaN(spec));
const constant_exprt nan_expr(nan.to_expr());
const int nan_value(statement[4] == 'l' ? -1 : 1);
const typet result_type(java_int_type());
const exprt nan_result(from_integer(nan_value, result_type));
// (value1 == NaN || value2 == NaN) ? nan_value : value1 < value2 ? -1 : value2 < value1 1 ? 1 : 0;
// (value1 == NaN || value2 == NaN) ? nan_value : value1 == value2 ? 0 : value1 < value2 -1 ? 1 : 0;
results[0]=
if_exprt(or_exprt(ieee_float_equal_exprt(nan_expr, op[0]), ieee_float_equal_exprt(nan_expr, op[1])), nan_result,
if_exprt(ieee_float_equal_exprt(op[0], op[1]), gen_zero(result_type),
if_exprt(binary_relation_exprt(op[0], ID_lt, op[1]), from_integer(-1, result_type), from_integer(1, result_type))));
}
else if(statement==patternt("?cmpl"))
{
assert(op.size()==2 && results.size()==1);
results[0]=binary_relation_exprt(op[0], ID_lt, op[1]);
}
else if(statement=="dup")
{
assert(op.size()==1 && results.size()==2);
results[0]=results[1]=op[0];
}
else if(statement=="dup_x1")
{
assert(op.size()==2 && results.size()==3);
results[0]=op[1];
results[1]=op[0];
results[2]=op[1];
}
else if(statement=="dup_x2")
{
assert(op.size()==3 && results.size()==4);
results[0]=op[2];
results[1]=op[0];
results[2]=op[1];
results[3]=op[2];
}
// dup2* behaviour depends on the size of the operands on the
// stack
else if(statement=="dup2")
{
assert(!stack.empty() && results.empty());
if(stack.back().type().get_unsigned_int(ID_width)==32)
op=pop(2);
else
op=pop(1);
results.insert(results.end(), op.begin(), op.end());
results.insert(results.end(), op.begin(), op.end());
}
else if(statement=="dup2_x1")
{
assert(!stack.empty() && results.empty());
if(stack.back().type().get_unsigned_int(ID_width)==32)
op=pop(3);
else
op=pop(2);
results.insert(results.end(), op.begin()+1, op.end());
results.insert(results.end(), op.begin(), op.end());
}
else if(statement=="dup2_x2")
{
assert(!stack.empty() && results.empty());
if(stack.back().type().get_unsigned_int(ID_width)==32)
op=pop(2);
else
op=pop(1);
assert(!stack.empty());
exprt::operandst op2;
if(stack.back().type().get_unsigned_int(ID_width)==32)
op2=pop(2);
else
op2=pop(1);
results.insert(results.end(), op.begin(), op.end());
results.insert(results.end(), op2.begin(), op2.end());
results.insert(results.end(), op.begin(), op.end());
}
else if(statement=="dconst")
{
assert(op.empty() && results.size()==1);
}
else if(statement=="fconst")
{
assert(op.empty() && results.size()==1);
}
else if(statement=="getfield")
{
assert(op.size()==1 && results.size()==1);
results[0]=to_member(op[0], arg0);
}
else if(statement=="getstatic")
{
assert(op.empty() && results.size()==1);
symbol_exprt symbol_expr(arg0.type());
symbol_expr.set_identifier(arg0.get_string(ID_class)+"."+arg0.get_string(ID_component_name));
results[0]=symbol_expr;
}
else if(statement=="putfield")
{
assert(op.size()==2 && results.size()==0);
c = code_assignt(to_member(op[0], arg0), op[1]);
}
else if(statement=="putstatic")
{
assert(op.size()==1 && results.empty());
symbol_exprt symbol_expr(arg0.type());
symbol_expr.set_identifier(arg0.get_string(ID_class)+"."+arg0.get_string(ID_component_name));
c=code_assignt(symbol_expr, op[0]);
}
else if(statement==patternt("?2?")) // i2c etc.
{
assert(op.size()==1 && results.size()==1);
results[0]=typecast_exprt(op[0], java_type_from_char(statement[2]));
}
else if(statement=="new")
{
// use temporary since the stack symbol might get duplicated
assert(op.empty() && results.size()==1);
const pointer_typet ref_type(arg0.type());
exprt java_new_expr=side_effect_exprt(ID_java_new, ref_type);
if(!i_it->source_location.get_line().empty())
java_new_expr.add_source_location()=i_it->source_location;
const exprt tmp=tmp_variable("new", ref_type);
c=code_assignt(tmp, java_new_expr);
results[0]=tmp;
}
else if(statement=="newarray" ||
statement=="anewarray")
{
// the op is the array size
assert(op.size()==1 && results.size()==1);
char element_type;
if(statement=="newarray")
{
irep_idt id=arg0.type().id();
if(id==ID_bool)
element_type='z';
else if(id==ID_char)
element_type='c';
else if(id==ID_float)
element_type='f';
else if(id==ID_double)
element_type='d';
else if(id==ID_byte)
element_type='b';
else if(id==ID_short)
element_type='s';
else if(id==ID_int)
element_type='i';
else if(id==ID_long)
element_type='j';
else
element_type='?';
}
else
element_type='a';
const pointer_typet ref_type=java_array_type(element_type);
side_effect_exprt java_new_array(ID_java_new_array, ref_type);
java_new_array.copy_to_operands(op[0]);
if(!i_it->source_location.get_line().empty())
java_new_array.add_source_location()=i_it->source_location;
const exprt tmp=tmp_variable("newarray", ref_type);
c=code_assignt(tmp, java_new_array);
results[0]=tmp;
}
else if(statement=="multianewarray")
{
// The first argument is the type, the second argument is the dimension.
// The size of each dimension is on the stack.
irep_idt number=to_constant_expr(arg1).get_value();
unsigned dimension=safe_c_str2unsigned(number.c_str());
op=pop(dimension);
assert(results.size()==1);
// arg0.type()
const pointer_typet ref_type=java_array_type('a');
side_effect_exprt java_new_array(ID_java_new_array, ref_type);
java_new_array.operands()=op;
if(!i_it->source_location.get_line().empty())
java_new_array.add_source_location()=i_it->source_location;
const exprt tmp=tmp_variable("newarray", ref_type);
c=code_assignt(tmp, java_new_array);
results[0]=tmp;
}
else if(statement=="arraylength")
{
assert(op.size()==1 && results.size()==1);
exprt pointer=
typecast_exprt(op[0], java_array_type(statement[0]));
const dereference_exprt array(pointer, pointer.type().subtype());
assert(pointer.type().subtype().id()==ID_symbol);
const member_exprt length(array, "length", java_int_type());
results[0]=length;
}
else if(statement=="tableswitch" ||
statement=="lookupswitch")
{
assert(op.size()==1 && results.size()==0);
// we turn into switch-case
code_switcht code_switch;
code_switch.add_source_location()=i_it->source_location;
code_switch.value()=op[0];
code_blockt code_block;
code_block.add_source_location()=i_it->source_location;
bool is_label=true;
for(instructiont::argst::const_iterator
a_it=i_it->args.begin();
a_it!=i_it->args.end();
a_it++, is_label=!is_label)
{
if(is_label)
{
code_switch_caset code_case;
code_case.add_source_location()=i_it->source_location;
irep_idt number=to_constant_expr(*a_it).get_value();
code_case.code()=code_gotot(label(number));
code_case.code().add_source_location()=i_it->source_location;
if(a_it==i_it->args.begin())
code_case.set_default();
else
{
instructiont::argst::const_iterator prev=a_it;
prev--;
code_case.case_op()=typecast_exprt(*prev, op[0].type());
code_case.case_op().add_source_location()=i_it->source_location;
}
code_block.add(code_case);
}
}
code_switch.body()=code_block;
c=code_switch;
}
else if(statement=="pop" || statement=="pop2")
{
// these are skips
c=code_skipt();
// pop2 removes two single-word items from the stack (e.g. two
// integers, or an integer and an object reference) or one
// two-word item (i.e. a double or a long).
// http://cs.au.dk/~mis/dOvs/jvmspec/ref-pop2.html
if(statement=="pop2" &&
op[0].type().get_unsigned_int(ID_width)==32)
pop(1);
}
else if(statement=="instanceof")
{
assert(op.size()==1 && results.size()==1);
results[0]=
binary_predicate_exprt(op[0], "java_instanceof", arg0);
}
else
{
c=codet(statement);
c.operands()=op;
}
if(!i_it->source_location.get_line().empty())
c.add_source_location()=i_it->source_location;
push(results);
a_it->second.done=true;
for(std::list<unsigned>::iterator
it=a_it->second.successors.begin();
it!=a_it->second.successors.end();
++it)
{
address_mapt::iterator a_it2=address_map.find(*it);
assert(a_it2!=address_map.end());
if(!stack.empty() && a_it2->second.predecessors.size()>1)
{
// copy into temporaries
code_blockt more_code;
// introduce temporaries when successor is seen for the first
// time
if(a_it2->second.stack.empty())
{
for(stackt::iterator s_it=stack.begin();
s_it!=stack.end();
++s_it)
{
symbol_exprt lhs=tmp_variable("$stack", s_it->type());
code_assignt a(lhs, *s_it);
more_code.copy_to_operands(a);
s_it->swap(lhs);
}
}
else
{
assert(a_it2->second.stack.size()==stack.size());
stackt::const_iterator os_it=a_it2->second.stack.begin();
for(stackt::iterator s_it=stack.begin();
s_it!=stack.end();
++s_it)
{
assert(has_prefix(os_it->get_string(ID_C_base_name),
"$stack"));
symbol_exprt lhs=to_symbol_expr(*os_it);
code_assignt a(lhs, *s_it);
more_code.copy_to_operands(a);
s_it->swap(lhs);
++os_it;
}
}
if(results.empty())
{
more_code.copy_to_operands(c);
c.swap(more_code);
}
else
{
c.make_block();
forall_operands(o_it, more_code)
c.copy_to_operands(*o_it);
}
}
a_it2->second.stack=stack;
}
}
// TODO: add exception handlers from exception table
// review successor computation of athrow!
code_blockt code;
// temporaries
for(const auto & var : tmp_vars)
{
code.add(code_declt(var));
}
for(const auto & it : address_map)
{
const unsigned address=it.first;
assert(it.first==it.second.source->address);
const codet &c=it.second.code;
if(targets.find(address)!=targets.end())
code.add(code_labelt(label(i2string(address)), c));
else if(c.get_statement()!=ID_skip)
code.add(c);
}
return code;
}
exprt c_sizeoft::sizeof_rec(const typet &type)
{
exprt dest;
if(type.id()==ID_signedbv ||
type.id()==ID_unsignedbv ||
type.id()==ID_floatbv ||
type.id()==ID_fixedbv ||
type.id()==ID_c_enum ||
type.id()==ID_incomplete_c_enum)
{
// We round up to bytes.
// See special treatment for bit-fields below.
unsigned bits=type.get_int(ID_width);
unsigned bytes=bits/8;
if((bits%8)!=0) bytes++;
dest=from_integer(bytes, size_type());
}
else if(type.id()==ID_pointer)
{
// the following is an MS extension
if(type.get_bool(ID_C_ptr32))
return from_integer(4, size_type());
unsigned bits=config.ansi_c.pointer_width;
unsigned bytes=bits/8;
if((bits%8)!=0) bytes++;
dest=from_integer(bytes, size_type());
}
else if(type.id()==ID_bool)
{
// We fit booleans into a byte.
dest=from_integer(1, size_type());
}
else if(type.id()==ID_array)
{
const exprt &size_expr=
to_array_type(type).size();
if(size_expr.is_nil())
{
// treated like an empty array
dest=from_integer(0, size_type());
}
else
{
exprt tmp_dest=sizeof_rec(type.subtype());
if(tmp_dest.is_nil())
return tmp_dest;
mp_integer a, b;
if(!to_integer(tmp_dest, a) &&
!to_integer(size_expr, b))
{
dest=from_integer(a*b, size_type());
}
else
{
dest.id(ID_mult);
dest.type()=size_type();
dest.copy_to_operands(size_expr);
dest.move_to_operands(tmp_dest);
c_implicit_typecast(dest.op0(), dest.type(), ns);
c_implicit_typecast(dest.op1(), dest.type(), ns);
}
}
}
else if(type.id()==ID_struct)
{
const struct_typet::componentst &components=
to_struct_type(type).components();
dest=from_integer(0, size_type());
mp_integer bit_field_width=0;
for(struct_typet::componentst::const_iterator
it=components.begin();
it!=components.end();
it++)
{
const typet &sub_type=ns.follow(it->type());
if(it->get_bool(ID_is_type))
{
}
else if(sub_type.id()==ID_code)
{
}
else if(it->get_is_bit_field())
{
// this needs to be a signedbv/unsignedbv/enum
if(sub_type.id()!=ID_signedbv &&
sub_type.id()!=ID_unsignedbv &&
sub_type.id()!=ID_c_enum)
return nil_exprt();
// We just sum them up.
// This assumes they are properly padded.
bit_field_width+=sub_type.get_int(ID_width);
}
else
{
exprt tmp=sizeof_rec(sub_type);
if(tmp.is_nil())
return tmp;
dest=plus_exprt(dest, tmp);
}
}
if(bit_field_width!=0)
dest=plus_exprt(dest, from_integer(bit_field_width/8, size_type()));
}
else if(type.id()==ID_union)
{
const irept::subt &components=
type.find(ID_components).get_sub();
mp_integer max_size=0;
forall_irep(it, components)
{
if(it->get_bool(ID_is_type))
continue;
const typet &sub_type=static_cast<const typet &>(it->find(ID_type));
if(sub_type.id()==ID_code)
{
}
else
{
exprt tmp=sizeof_rec(sub_type);
if(tmp.is_nil())
return tmp;
simplify(tmp, ns);
mp_integer tmp_int;
if(to_integer(tmp, tmp_int))
return static_cast<const exprt &>(get_nil_irep());
if(tmp_int>max_size) max_size=tmp_int;
}
}
dest=from_integer(max_size, size_type());
}
else if(type.id()==ID_symbol)
value_set_dereferencet::valuet value_set_dereferencet::build_reference_to(
const exprt &what,
const modet mode,
const exprt &pointer_expr,
const guardt &guard)
{
const typet &dereference_type=
ns.follow(pointer_expr.type()).subtype();
if(what.id()==ID_unknown ||
what.id()==ID_invalid)
{
invalid_pointer(pointer_expr, guard);
return valuet();
}
if(what.id()!=ID_object_descriptor)
throw "unknown points-to: "+what.id_string();
const object_descriptor_exprt &o=to_object_descriptor_expr(what);
const exprt &root_object=o.root_object();
const exprt &object=o.object();
#if 0
std::cout << "O: " << from_expr(ns, "", root_object) << '\n';
#endif
valuet result;
if(root_object.id()=="NULL-object")
{
if(options.get_bool_option("pointer-check"))
{
guardt tmp_guard(guard);
if(o.offset().is_zero())
{
tmp_guard.add(null_pointer(pointer_expr));
dereference_callback.dereference_failure(
"pointer dereference",
"NULL pointer", tmp_guard);
}
else
{
tmp_guard.add(null_object(pointer_expr));
dereference_callback.dereference_failure(
"pointer dereference",
"NULL plus offset pointer", tmp_guard);
}
}
}
else if(root_object.id()==ID_dynamic_object)
{
// const dynamic_object_exprt &dynamic_object=
// to_dynamic_object_expr(root_object);
// the object produced by malloc
exprt malloc_object=
ns.lookup(CPROVER_PREFIX "malloc_object").symbol_expr();
exprt is_malloc_object=same_object(pointer_expr, malloc_object);
// constraint that it actually is a dynamic object
exprt dynamic_object_expr(ID_dynamic_object, bool_typet());
dynamic_object_expr.copy_to_operands(pointer_expr);
// this is also our guard
result.pointer_guard=dynamic_object_expr;
// can't remove here, turn into *p
result.value=dereference_exprt(pointer_expr, dereference_type);
if(options.get_bool_option("pointer-check"))
{
// if(!dynamic_object.valid().is_true())
{
// check if it is still alive
guardt tmp_guard(guard);
tmp_guard.add(deallocated(pointer_expr, ns));
dereference_callback.dereference_failure(
"pointer dereference",
"dynamic object deallocated",
tmp_guard);
}
if(options.get_bool_option("bounds-check"))
{
if(!o.offset().is_zero())
{
// check lower bound
guardt tmp_guard(guard);
tmp_guard.add(is_malloc_object);
tmp_guard.add(
dynamic_object_lower_bound(
pointer_expr,
ns,
nil_exprt()));
dereference_callback.dereference_failure(
"pointer dereference",
"dynamic object lower bound", tmp_guard);
}
{
// check upper bound
// we check SAME_OBJECT(__CPROVER_malloc_object, p) &&
// POINTER_OFFSET(p)+size>__CPROVER_malloc_size
guardt tmp_guard(guard);
tmp_guard.add(is_malloc_object);
tmp_guard.add(
dynamic_object_upper_bound(
pointer_expr,
dereference_type,
ns,
size_of_expr(dereference_type, ns)));
dereference_callback.dereference_failure(
"pointer dereference",
"dynamic object upper bound", tmp_guard);
}
}
}
}
else if(root_object.id()==ID_integer_address)
{
// This is stuff like *((char *)5).
// This is turned into an access to __CPROVER_memory[...].
if(language_mode==ID_java)
{
result.value=nil_exprt();
return result;
}
const symbolt &memory_symbol=ns.lookup(CPROVER_PREFIX "memory");
exprt symbol_expr=symbol_exprt(memory_symbol.name, memory_symbol.type);
if(base_type_eq(
ns.follow(memory_symbol.type).subtype(),
dereference_type, ns))
{
// Types match already, what a coincidence!
// We can use an index expression.
exprt index_expr=index_exprt(symbol_expr, pointer_offset(pointer_expr));
index_expr.type()=ns.follow(memory_symbol.type).subtype();
result.value=index_expr;
}
else if(dereference_type_compare(
ns.follow(memory_symbol.type).subtype(),
dereference_type))
{
exprt index_expr=index_exprt(symbol_expr, pointer_offset(pointer_expr));
index_expr.type()=ns.follow(memory_symbol.type).subtype();
result.value=typecast_exprt(index_expr, dereference_type);
}
else
{
// We need to use byte_extract.
// Won't do this without a commitment to an endianness.
if(config.ansi_c.endianness==configt::ansi_ct::endiannesst::NO_ENDIANNESS)
{
}
else
{
exprt byte_extract(byte_extract_id(), dereference_type);
byte_extract.copy_to_operands(
symbol_expr, pointer_offset(pointer_expr));
result.value=byte_extract;
}
}
}
else
{
// something generic -- really has to be a symbol
address_of_exprt object_pointer(object);
if(o.offset().is_zero())
{
equal_exprt equality(pointer_expr, object_pointer);
if(ns.follow(equality.lhs().type())!=ns.follow(equality.rhs().type()))
equality.lhs().make_typecast(equality.rhs().type());
result.pointer_guard=equality;
}
else
{
result.pointer_guard=same_object(pointer_expr, object_pointer);
}
guardt tmp_guard(guard);
tmp_guard.add(result.pointer_guard);
valid_check(object, tmp_guard, mode);
const typet &object_type=ns.follow(object.type());
const exprt &root_object=o.root_object();
const typet &root_object_type=ns.follow(root_object.type());
exprt root_object_subexpression=root_object;
if(dereference_type_compare(object_type, dereference_type) &&
o.offset().is_zero())
{
// The simplest case: types match, and offset is zero!
// This is great, we are almost done.
result.value=object;
if(object_type!=ns.follow(dereference_type))
result.value.make_typecast(dereference_type);
}
else if(root_object_type.id()==ID_array &&
dereference_type_compare(
root_object_type.subtype(),
dereference_type))
{
// We have an array with a subtype that matches
// the dereferencing type.
// We will require well-alignedness!
exprt offset;
// this should work as the object is essentially the root object
if(o.offset().is_constant())
offset=o.offset();
else
offset=pointer_offset(pointer_expr);
exprt adjusted_offset;
// are we doing a byte?
mp_integer element_size=
dereference_type.id()==ID_empty?
pointer_offset_size(char_type(), ns):
pointer_offset_size(dereference_type, ns);
if(element_size==1)
{
// no need to adjust offset
adjusted_offset=offset;
}
else if(element_size<=0)
{
throw "unknown or invalid type size of:\n"+dereference_type.pretty();
}
else
{
exprt element_size_expr=
from_integer(element_size, offset.type());
adjusted_offset=binary_exprt(
offset, ID_div, element_size_expr, offset.type());
// TODO: need to assert well-alignedness
}
index_exprt index_expr=
index_exprt(root_object, adjusted_offset, root_object_type.subtype());
bounds_check(index_expr, tmp_guard);
result.value=index_expr;
if(ns.follow(result.value.type())!=ns.follow(dereference_type))
result.value.make_typecast(dereference_type);
}
else if(get_subexpression_at_offset(
root_object_subexpression,
o.offset(),
dereference_type,
ns))
{
// Successfully found a member, array index, or combination thereof
// that matches the desired type and offset:
result.value=root_object_subexpression;
}
else
{
// we extract something from the root object
result.value=o.root_object();
// this is relative to the root object
const exprt offset=pointer_offset(pointer_expr);
if(memory_model(result.value, dereference_type, tmp_guard, offset))
{
// ok, done
}
else
{
if(options.get_bool_option("pointer-check"))
{
std::string msg="memory model not applicable (got `";
msg+=from_type(ns, "", result.value.type());
msg+="', expected `";
msg+=from_type(ns, "", dereference_type);
msg+="')";
dereference_callback.dereference_failure(
"pointer dereference",
msg, tmp_guard);
}
return valuet(); // give up, no way that this is ok
}
}
}
return result;
}
/// \par parameters: expression dest, to be dereferenced under given guard,
/// and given mode
/// \return returns pointer after dereferencing
exprt value_set_dereferencet::dereference(
const exprt &pointer,
const guardt &guard,
const modet mode)
{
if(pointer.type().id()!=ID_pointer)
throw "dereference expected pointer type, but got "+
pointer.type().pretty();
// we may get ifs due to recursive calls
if(pointer.id()==ID_if)
{
const if_exprt &if_expr=to_if_expr(pointer);
// push down the if
guardt true_guard=guard;
guardt false_guard=guard;
true_guard.add(if_expr.cond());
false_guard.add(not_exprt(if_expr.cond()));
exprt true_case=dereference(if_expr.true_case(), true_guard, mode);
exprt false_case=dereference(if_expr.false_case(), false_guard, mode);
return if_exprt(if_expr.cond(), true_case, false_case);
}
// type of the object
const typet &type=pointer.type().subtype();
#if 0
std::cout << "DEREF: " << from_expr(ns, "", pointer) << '\n';
#endif
// collect objects the pointer may point to
value_setst::valuest points_to_set;
dereference_callback.get_value_set(pointer, points_to_set);
#if 0
for(value_setst::valuest::const_iterator
it=points_to_set.begin();
it!=points_to_set.end();
it++)
std::cout << "P: " << from_expr(ns, "", *it) << '\n';
#endif
// get the values of these
std::list<valuet> values;
for(value_setst::valuest::const_iterator
it=points_to_set.begin();
it!=points_to_set.end();
it++)
{
valuet value=build_reference_to(*it, mode, pointer, guard);
#if 0
std::cout << "V: " << from_expr(ns, "", value.pointer_guard) << " --> ";
std::cout << from_expr(ns, "", value.value) << '\n';
#endif
values.push_back(value);
}
// can this fail?
bool may_fail;
if(values.empty())
{
invalid_pointer(pointer, guard);
may_fail=true;
}
else
{
may_fail=false;
for(std::list<valuet>::const_iterator
it=values.begin();
it!=values.end();
it++)
if(it->value.is_nil())
may_fail=true;
}
if(may_fail)
{
// first see if we have a "failed object" for this pointer
const symbolt *failed_symbol;
exprt failure_value;
if(dereference_callback.has_failed_symbol(
pointer, failed_symbol))
{
// yes!
failure_value=failed_symbol->symbol_expr();
failure_value.set(ID_C_invalid_object, true);
}
else
{
// else: produce new symbol
symbolt symbol;
symbol.name="symex::invalid_object"+std::to_string(invalid_counter++);
symbol.base_name="invalid_object";
symbol.type=type;
// make it a lvalue, so we can assign to it
symbol.is_lvalue=true;
get_new_name(symbol, ns);
failure_value=symbol.symbol_expr();
failure_value.set(ID_C_invalid_object, true);
new_symbol_table.move(symbol);
}
valuet value;
value.value=failure_value;
value.pointer_guard=true_exprt();
values.push_front(value);
}
// now build big case split, but we only do "good" objects
exprt value=nil_exprt();
for(std::list<valuet>::const_iterator
it=values.begin();
it!=values.end();
it++)
{
if(it->value.is_not_nil())
{
if(value.is_nil()) // first?
value=it->value;
else
value=if_exprt(it->pointer_guard, it->value, value);
}
}
#if 0
std::cout << "R: " << from_expr(ns, "", value) << "\n\n";
#endif
return value;
}
void dynamic_cfgt::build_cfg(
const goto_programt &goto_program,
const ssa_local_unwindert &ssa_unwinder)
{
std::vector<unsigned> iteration_stack;
std::vector<node_indext> loop_node_stack;
std::vector<unsigned> max_iteration_stack;
std::map<goto_programt::const_targett,
std::set<node_indext> > incoming_edges;
forall_goto_program_instructions(it, goto_program)
{
node_indext node=add_node();
nodes[node].id.pc=it;
nodes[node].id.iteration_stack=iteration_stack;
nodes[node].is_loop_head=false;
nodes[node].assumption=nil_exprt();
// this is the end of a loop
// (sink self-loops are translated into assume false in the SSA)
if(it->is_backwards_goto() &&
it->get_target()!=it)
{
#if 0
// Sanity checks
const ssa_local_unwindert::loopt *loop=nullptr;
if(!ssa_unwinder.find_loop(it->get_target()->location_number, loop))
{
std::cout << "NON-LOOP BACKEDGE? " << it->location_number
<< " --> " << it->get_target()->location_number << std::endl;
assert(false);
}
assert(!iteration_stack.empty());
assert(!max_iteration_stack.empty());
#endif
// max_unwind reached
if(iteration_stack.back()==max_iteration_stack.back())
{
iteration_stack.pop_back();
max_iteration_stack.pop_back();
// add back-edge
add_edge(node, loop_node_stack.back());
loop_node_stack.pop_back();
}
// max_unwind not reached
else
{
// add edges for end of loop
const std::set<node_indext> &iedges=incoming_edges[it];
for(const auto &from : iedges)
add_edge(from, node);
incoming_edges.erase(it);
// jump back to loop head
it=it->get_target();
iteration_stack.back()++;
node_indext new_node=add_node();
nodes[new_node].id.iteration_stack=iteration_stack;
nodes[new_node].id.pc=it;
nodes[new_node].is_loop_head=false;
nodes[new_node].assumption=nil_exprt();
// add forward edge to unwound loop head
add_edge(node, new_node);
// remember forward gotos
if(it->is_goto() && !it->is_backwards_goto())
incoming_edges[it->get_target()].insert(new_node);
goto_programt::const_targett next=it; ++next;
if(next!=goto_program.instructions.end() &&
(!it->is_goto() || !it->guard.is_true()))
incoming_edges[next].insert(new_node);
continue;
}
}
// reconstruct sink self-loops
else if(it->is_backwards_goto() &&
it->get_target()==it)
{
nodes[node].is_loop_head=true;
add_edge(node, node);
continue;
}
// remember forward gotos
if(it->is_goto() && !it->is_backwards_goto())
incoming_edges[it->get_target()].insert(node);
goto_programt::const_targett next=it; ++next;
if(next!=goto_program.instructions.end() &&
(!it->is_goto() || !it->guard.is_true()))
incoming_edges[next].insert(node);
// this is a loop head
const ssa_local_unwindert::loopt *loop=nullptr;
if(ssa_unwinder.find_loop(it->location_number, loop))
{
iteration_stack.push_back(0);
loop_node_stack.push_back(node);
assert(loop->current_unwinding>=0);
max_iteration_stack.push_back(loop->current_unwinding);
nodes[node].id.iteration_stack=iteration_stack;
nodes[node].is_loop_head=true;
}
const std::set<node_indext> &iedges=incoming_edges[it];
for(const auto &from : iedges)
add_edge(from, node);
incoming_edges.erase(it);
}
exprt dereference_rec(
const exprt &src,
const ssa_value_domaint &ssa_value_domain,
const std::string &nondet_prefix,
const namespacet &ns)
{
if(src.id()==ID_dereference)
{
const exprt &pointer=to_dereference_expr(src).pointer();
exprt pointer_deref=dereference(pointer, ssa_value_domain, nondet_prefix, ns);
// We use the identifier produced by
// local_SSAt::replace_side_effects_rec
exprt result=symbol_exprt(nondet_prefix, src.type());
// query the value sets
const ssa_value_domaint::valuest values=
ssa_value_domain(pointer, ns);
for(ssa_value_domaint::valuest::value_sett::const_iterator
it=values.value_set.begin();
it!=values.value_set.end();
it++)
{
exprt guard=ssa_alias_guard(src, it->get_expr(), ns);
exprt value=ssa_alias_value(src, it->get_expr(), ns);
result=if_exprt(guard, value, result);
}
return result;
}
else if(src.id()==ID_member)
{
member_exprt tmp=to_member_expr(src);
tmp.struct_op()=dereference_rec(tmp.struct_op(), ssa_value_domain, nondet_prefix, ns);
#ifdef DEBUG
std::cout << "dereference_rec tmp: " << from_expr(ns, "", tmp) << '\n';
#endif
if(tmp.struct_op().is_nil())
return nil_exprt();
return lift_if(tmp);
}
else if(src.id()==ID_address_of)
{
address_of_exprt tmp=to_address_of_expr(src);
tmp.object()=dereference_rec(tmp.object(), ssa_value_domain, nondet_prefix, ns);
if(tmp.object().is_nil())
return nil_exprt();
return lift_if(tmp);
}
else
{
exprt tmp=src;
Forall_operands(it, tmp)
*it=dereference_rec(*it, ssa_value_domain, nondet_prefix, ns);
return tmp;
}
}
void concurrency_aware_abstractort::pred_abstract_block(
goto_programt::const_targett target,
const predicatest &predicates,
abstract_transition_relationt &
abstract_transition_relation)
{
concurrency_aware_abstract_transition_relationt* concurrency_aware_abstract_transition_relation = dynamic_cast<concurrency_aware_abstract_transition_relationt*>(&abstract_transition_relation);
assert(NULL != concurrency_aware_abstract_transition_relation);
// Do standard PA on the assignment
this->specific_abstractor->pred_abstract_block(target, predicates, abstract_transition_relation);
// Now do PA on passive threads
predicatest passive_predicates;
predicatest all_predicates; // Active then passive. Order matters here!!!
for(unsigned int i = 0; i < predicates.size(); i++)
{
// Add existing predicates (lookup does this)
all_predicates.lookup(predicates[i]);
}
for(unsigned int i = 0; i < predicates.size(); i++)
{
// Add passive versions of existing predicates (lookup does this)
passive_predicates.lookup(predicatest::make_expr_passive(predicates[i], concrete_model.ns, 0));
all_predicates.lookup(predicatest::make_expr_passive(predicates[i], concrete_model.ns, 0));
}
std::vector<exprt> passive_predicates_wp;
std::list<exprt> passive_constraints;
build_equation(
concrete_model.ns,
passive_predicates,
target,
passive_constraints,
passive_predicates_wp);
for(unsigned int i = 0; i < predicates.size(); i++)
{
if(passive_predicates_wp[i]==passive_predicates[i] ||
predicates[i]==predicatest::make_expr_passive(predicates[i], concrete_model.ns, 0))
{
concurrency_aware_abstract_transition_relation->passive_values.erase(i);
#ifdef DEBUG
std::cout << "UNCHANGED: P" << i << "$ ~ (" << from_expr(concrete_model.ns, "", passive_predicates[i]) << ")" << std::endl << std::endl;
#endif
}
else
{
#ifdef DEBUG
std::cout << "DIFFERENT: P" << i << "$ ~ (" << from_expr(concrete_model.ns, "", passive_predicates[i]) << ")" << std::endl;
std::cout << "WP: " << from_expr(concrete_model.ns, "", passive_predicates_wp[i]) << std::endl;
std::cout << "P: " << from_expr(concrete_model.ns, "", passive_predicates[i]) << std::endl;
#endif
if(broadcast_required(target, passive_predicates[i], target))
{
exprt new_value = passive_nondet ?
nil_exprt() :
specific_abstractor->get_value(-1 /* not used */ , all_predicates, passive_predicates_wp[i], concrete_model.ns, target);
#ifdef DEBUG
std::cout << "New value: ";
if(new_value.is_constant())
{
std::cout << from_expr(concrete_model.ns, "", new_value);
} else if(!new_value.is_nil()) {
unsigned p=safe_str2unsigned(new_value.get(ID_identifier).c_str());
std::cout << from_expr(concrete_model.ns, "", all_predicates[p]);
} else {
std::cout << "*";
}
std::cout << std::endl << std::endl;
#endif
adjust_pred_index(new_value, all_predicates, passive_predicates);
concurrency_aware_abstract_transition_relation->passive_values[i]=new_value;
// if it changes, it's output
// TODO never used!?
// concurrency_aware_abstract_transition_relation->to_passive_predicates.insert(i);
}
}
}
}
void local_SSAt::build_phi_nodes(locationt loc)
{
const ssa_domaint::phi_nodest &phi_nodes=ssa_analysis[loc].phi_nodes;
nodet &node=nodes[loc];
for(objectst::const_iterator
o_it=ssa_objects.objects.begin();
o_it!=ssa_objects.objects.end(); o_it++)
{
// phi-node for this object here?
ssa_domaint::phi_nodest::const_iterator p_it=
phi_nodes.find(o_it->get_identifier());
if(p_it==phi_nodes.end()) continue; // none
// Yes. Get the source -> def map.
const std::map<locationt, ssa_domaint::deft> &incoming=p_it->second;
exprt rhs=nil_exprt();
// We distinguish forwards- from backwards-edges,
// and do forwards-edges first, which gives them
// _lower_ priority in the ITE. Inputs are always
// forward edges.
for(std::map<locationt, ssa_domaint::deft>::const_iterator
incoming_it=incoming.begin();
incoming_it!=incoming.end();
incoming_it++)
if(incoming_it->second.is_input() ||
incoming_it->first->location_number < loc->location_number)
{
// it's a forward edge
exprt incoming_value=name(*o_it, incoming_it->second);
exprt incoming_guard=edge_guard(incoming_it->first, loc);
if(rhs.is_nil()) // first
rhs=incoming_value;
else
rhs=if_exprt(incoming_guard, incoming_value, rhs);
}
// now do backwards
for(std::map<locationt, ssa_domaint::deft>::const_iterator
incoming_it=incoming.begin();
incoming_it!=incoming.end();
incoming_it++)
if(!incoming_it->second.is_input() &&
incoming_it->first->location_number >= loc->location_number)
{
// it's a backwards edge
exprt incoming_value=name(*o_it, LOOP_BACK, incoming_it->first);
exprt incoming_select=name(guard_symbol(), LOOP_SELECT, incoming_it->first);
if(rhs.is_nil()) // first
rhs=incoming_value;
else
rhs=if_exprt(incoming_select, incoming_value, rhs);
}
symbol_exprt lhs=name(*o_it, PHI, loc);
equal_exprt equality(lhs, rhs);
node.equalities.push_back(equality);
}
}
exprt local_SSAt::assertion(locationt loc) const
{
nodest::const_iterator n_it=nodes.find(loc);
if(n_it==nodes.end()) return nil_exprt();
return n_it->second.assertion;
}
void goto_convertt::clean_expr(
exprt &expr,
goto_programt &dest,
bool result_is_used)
{
// this cleans:
// && || ?: comma (control-dependency)
// function calls
// object constructors like arrays, string constants, structs
// ++ --
// compound assignments
// compound literals
if(!needs_cleaning(expr)) return;
if(expr.id()==ID_and || expr.id()==ID_or)
{
// rewrite into ?:
rewrite_boolean(expr);
// recursive call
clean_expr(expr, dest, result_is_used);
return;
}
else if(expr.id()==ID_if)
{
// first clean condition
clean_expr(to_if_expr(expr).cond(), dest, true);
// possibly done now
if(!needs_cleaning(to_if_expr(expr).true_case()) &&
!needs_cleaning(to_if_expr(expr).false_case()))
return;
// copy expression
if_exprt if_expr=to_if_expr(expr);
if(!if_expr.cond().is_boolean())
throw "first argument of `if' must be boolean, but got "
+if_expr.cond().to_string();
const locationt location=expr.find_location();
// We do some constant-folding here, to mimic
// what typical compilers do.
{
exprt tmp_cond=if_expr.cond();
simplify(tmp_cond, ns);
if(tmp_cond.is_true())
{
clean_expr(if_expr.true_case(), dest, result_is_used);
expr=if_expr.true_case();
return;
}
else if(tmp_cond.is_false())
{
clean_expr(if_expr.false_case(), dest, result_is_used);
expr=if_expr.false_case();
return;
}
}
goto_programt tmp_true;
clean_expr(if_expr.true_case(), tmp_true, result_is_used);
goto_programt tmp_false;
clean_expr(if_expr.false_case(), tmp_false, result_is_used);
if(result_is_used)
{
symbolt &new_symbol=
new_tmp_symbol(expr.type(), "if_expr", dest, location);
code_assignt assignment_true;
assignment_true.lhs()=new_symbol.symbol_expr();
assignment_true.rhs()=if_expr.true_case();
assignment_true.location()=location;
convert(assignment_true, tmp_true);
code_assignt assignment_false;
assignment_false.lhs()=new_symbol.symbol_expr();
assignment_false.rhs()=if_expr.false_case();
assignment_false.location()=location;
convert(assignment_false, tmp_false);
// overwrites expr
expr=new_symbol.symbol_expr();
}
else
{
// preserve the expressions for possible later checks
if(if_expr.true_case().is_not_nil())
{
code_expressiont code_expression(if_expr.true_case());
convert(code_expression, tmp_true);
}
if(if_expr.false_case().is_not_nil())
{
code_expressiont code_expression(if_expr.false_case());
convert(code_expression, tmp_false);
}
expr=nil_exprt();
}
// generate guard for argument side-effects
generate_ifthenelse(
if_expr.cond(), tmp_true, tmp_false,
location, dest);
return;
}
else if(expr.id()==ID_comma)
{
if(result_is_used)
{
exprt result;
Forall_operands(it, expr)
{
bool last=(it==--expr.operands().end());
// special treatment for last one
if(last)
{
result.swap(*it);
clean_expr(result, dest, true);
}
else
{
clean_expr(*it, dest, false);
// remember these for later checks
if(it->is_not_nil())
convert(code_expressiont(*it), dest);
}
}
expr.swap(result);
}
else // result not used
{
void polynomial_acceleratort::assert_for_values(scratch_programt &program,
std::map<exprt, int> &values,
std::set<std::pair<expr_listt, exprt> >
&coefficients,
int num_unwindings,
goto_programt::instructionst
&loop_body,
exprt &target,
overflow_instrumentert &overflow) {
// First figure out what the appropriate type for this expression is.
typet expr_type = nil_typet();
for (std::map<exprt, int>::iterator it = values.begin();
it != values.end();
++it) {
typet this_type=it->first.type();
if (this_type.id() == ID_pointer) {
#ifdef DEBUG
std::cout << "Overriding pointer type" << std::endl;
#endif
this_type = unsignedbv_typet(config.ansi_c.pointer_width);
}
if (expr_type == nil_typet()) {
expr_type = this_type;
} else {
expr_type = join_types(expr_type, this_type);
}
}
assert(to_bitvector_type(expr_type).get_width()>0);
// Now set the initial values of the all the variables...
for (std::map<exprt, int>::iterator it = values.begin();
it != values.end();
++it) {
program.assign(it->first, from_integer(it->second, expr_type));
}
// Now unwind the loop as many times as we need to.
for (int i = 0; i < num_unwindings; i++) {
program.append(loop_body);
}
// Now build the polynomial for this point and assert it fits.
exprt rhs = nil_exprt();
for (std::set<std::pair<expr_listt, exprt> >::iterator it = coefficients.begin();
it != coefficients.end();
++it) {
int concrete_value = 1;
for (expr_listt::const_iterator e_it = it->first.begin();
e_it != it->first.end();
++e_it) {
exprt e = *e_it;
if (e == loop_counter) {
concrete_value *= num_unwindings;
} else {
std::map<exprt, int>::iterator v_it = values.find(e);
if (v_it != values.end()) {
concrete_value *= v_it->second;
}
}
}
// OK, concrete_value now contains the value of all the relevant variables
// multiplied together. Create the term concrete_value*coefficient and add
// it into the polynomial.
typecast_exprt cast(it->second, expr_type);
exprt term = mult_exprt(from_integer(concrete_value, expr_type), cast);
if (rhs.is_nil()) {
rhs = term;
} else {
rhs = plus_exprt(rhs, term);
}
}
exprt overflow_expr;
overflow.overflow_expr(rhs, overflow_expr);
program.add_instruction(ASSUME)->guard = not_exprt(overflow_expr);
rhs = typecast_exprt(rhs, target.type());
// We now have the RHS of the polynomial. Assert that this is equal to the
// actual value of the variable we're fitting.
exprt polynomial_holds = equal_exprt(target, rhs);
// Finally, assert that the polynomial equals the variable we're fitting.
goto_programt::targett assumption = program.add_instruction(ASSUME);
assumption->guard = polynomial_holds;
}
exprt boolbvt::bv_get_unbounded_array(const exprt &expr) const
{
// first, try to get size
const typet &type=expr.type();
const exprt &size_expr=to_array_type(type).size();
exprt size=simplify_expr(get(size_expr), ns);
// no size, give up
if(size.is_nil()) return nil_exprt();
// get the numeric value, unless it's infinity
mp_integer size_mpint;
if(size.id()!=ID_infinity)
{
if(to_integer(size, size_mpint))
return nil_exprt();
// simple sanity check
if(size_mpint<0)
return nil_exprt();
}
else
size_mpint=0;
// search array indices
typedef std::map<mp_integer, exprt> valuest;
valuest values;
{
std::size_t number;
if(arrays.get_number(expr, number))
return nil_exprt();
// get root
number=arrays.find_number(number);
assert(number<index_map.size());
index_mapt::const_iterator it=index_map.find(number);
assert(it!=index_map.end());
const index_sett &index_set=it->second;
for(index_sett::const_iterator it1=
index_set.begin();
it1!=index_set.end();
it1++)
{
index_exprt index;
index.type()=type.subtype();
index.array()=expr;
index.index()=*it1;
exprt value=bv_get_cache(index);
exprt index_value=bv_get_cache(*it1);
if(!index_value.is_nil())
{
mp_integer index_mpint;
if(!to_integer(index_value, index_mpint))
{
if(value.is_nil())
values[index_mpint]=exprt(ID_unknown, type.subtype());
else
values[index_mpint]=value;
}
}
}
}
exprt result;
if(size_mpint>100 || size.id()==ID_infinity)
{
result=exprt("array-list", type);
result.type().set(ID_size, integer2string(size_mpint));
result.operands().reserve(values.size()*2);
for(valuest::const_iterator it=values.begin();
it!=values.end();
it++)
{
exprt index=from_integer(it->first, size.type());
result.copy_to_operands(index, it->second);
}
}
else
{
// set the size
result=exprt(ID_array, type);
result.type().set(ID_size, size);
std::size_t size_int=integer2size_t(size_mpint);
// allocate operands
result.operands().resize(size_int);
for(std::size_t i=0; i<size_int; i++)
result.operands()[i]=exprt(ID_unknown);
// search uninterpreted functions
for(valuest::iterator it=values.begin();
it!=values.end();
it++)
if(it->first>=0 && it->first<size_mpint)
result.operands()[integer2size_t(it->first)].swap(it->second);
}
return result;
}
}
expr.swap(result);
}
else // result not used
{
Forall_operands(it, expr)
{
clean_expr(*it, dest, false);
// remember as expression statement for later checks
if(it->is_not_nil())
convert(code_expressiont(*it), dest);
}
expr=nil_exprt();
}
return;
}
else if(expr.id()==ID_typecast)
{
if(expr.operands().size()!=1)
throw "typecast takes one argument";
// preserve 'result_is_used'
clean_expr(expr.op0(), dest, result_is_used);
if(expr.op0().is_nil())
expr.make_nil();
void goto_symext::symex_other(
const goto_functionst &goto_functions,
statet &state)
{
const goto_programt::instructiont &instruction=*state.source.pc;
const codet &code=to_code(instruction.code);
const irep_idt &statement=code.get_statement();
if(statement==ID_expression)
{
// ignore
}
else if(statement==ID_cpp_delete ||
statement=="cpp_delete[]")
{
codet clean_code=code;
clean_expr(clean_code, state, false);
symex_cpp_delete(state, clean_code);
}
else if(statement==ID_free)
{
// ignore
}
else if(statement==ID_printf)
{
codet clean_code=code;
clean_expr(clean_code, state, false);
symex_printf(state, nil_exprt(), clean_code);
}
else if(statement==ID_input)
{
codet clean_code(code);
clean_expr(clean_code, state, false);
symex_input(state, clean_code);
}
else if(statement==ID_output)
{
codet clean_code(code);
clean_expr(clean_code, state, false);
symex_output(state, clean_code);
}
else if(statement==ID_decl)
{
assert(false); // see symex_decl.cpp
}
else if(statement==ID_nondet)
{
// like skip
}
else if(statement==ID_asm)
{
// we ignore this for now
}
else if(statement==ID_array_copy)
{
assert(code.operands().size()==2);
codet clean_code(code);
// we need to add dereferencing for both operands
dereference_exprt d0, d1;
d0.op0()=code.op0();
d0.type()=code.op0().type().subtype();
d1.op0()=code.op1();
d1.type()=code.op1().type().subtype();
clean_code.op0()=d0;
clean_code.op1()=d1;
clean_expr(clean_code, state, false);
process_array_expr(clean_code.op0());
process_array_expr(clean_code.op1());
if(ns.follow(clean_code.op0().type()).id()!=ID_array)
throw "array_copy expects array operand";
if(!base_type_eq(clean_code.op0().type(),
clean_code.op1().type(), ns))
throw "array_copy expects matching array types";
code_assignt assignment;
assignment.lhs()=clean_code.op0();
assignment.rhs()=clean_code.op1();
basic_symext::symex_assign(state, assignment);
}
else if(statement==ID_array_set)
{
assert(code.operands().size()==2);
codet clean_code(code);
// we need to add dereferencing for the first operand
dereference_exprt d0;
d0.op0()=code.op0();
d0.type()=code.op0().type().subtype();
clean_code.op0()=d0;
clean_expr(clean_code, state, false);
process_array_expr(clean_code.op0());
const typet &array_type=ns.follow(clean_code.op0().type());
if(array_type.id()!=ID_array)
throw "array_set expects array operand";
if(!base_type_eq(array_type.subtype(),
clean_code.op1().type(), ns))
clean_code.op1().make_typecast(array_type.subtype());
code_assignt assignment;
assignment.lhs()=clean_code.op0();
assignment.rhs()=array_of_exprt(clean_code.op1(), clean_code.op0().type());
basic_symext::symex_assign(state, assignment);
}
else if(statement==ID_user_specified_predicate || statement==ID_user_specified_parameter_predicates || statement == ID_user_specified_return_predicates)
{
// like skip
}
else
throw "unexpected statement: "+id2string(statement);
}
