exprt address_canonizer(
const exprt &address,
const namespacet &ns)
{
assert(ns.follow(address.type()).id()==ID_pointer);
if(address.id()==ID_address_of)
{
const address_of_exprt &address_of_expr=
to_address_of_expr(address);
const exprt &object=address_of_expr.object();
if(object.id()==ID_dereference)
{
// &*x ---> x
return to_dereference_expr(object).pointer();
}
else if(object.id()==ID_member)
{
// get offset
exprt offset=member_offset_expr(to_member_expr(object), ns);
// &x.m ---> (&x)+offset
address_of_exprt address_of_expr(to_member_expr(object).struct_op());
exprt rec_result=address_canonizer(address_of_expr, ns); // rec. call
pointer_typet byte_pointer(unsigned_char_type());
typecast_exprt typecast_expr(rec_result, byte_pointer);
plus_exprt sum(typecast_expr, offset);
if(sum.type()!=address.type())
sum.make_typecast(address.type());
return sum;
}
else if(object.id()==ID_index)
{
// &(x[i]) ---> (&x)+i
address_of_exprt address_of_expr(to_index_expr(object).array());
exprt rec_result=address_canonizer(address_of_expr, ns); // rec. call
pointer_typet pointer_type;
pointer_type.subtype()=object.type();
typecast_exprt typecast_expr(rec_result, pointer_type);
plus_exprt sum(typecast_expr, to_index_expr(object).index());
if(sum.type()!=address.type())
sum.make_typecast(address.type());
return sum;
}
else if(object.id()==ID_symbol && is_iterator(object))
{
// address of iterator is dereferenced to a corresponding symbol -
// will be bound to real address during analysis
symbol_exprt iterator_addr(
id2string(to_symbol_expr(object).get_identifier())+"'addr",
address.type());
return iterator_addr;
}
else
return address;
}
else if(address.id()==ID_plus ||
address.id()==ID_minus)
{
// one of the operands needs to be a pointer
assert(address.operands().size()==2);
exprt tmp=address;
if(ns.follow(tmp.op0().type()).id()==ID_pointer)
{
tmp.op0()=address_canonizer(tmp.op0(), ns);
return tmp;
}
else if(ns.follow(tmp.op1().type()).id()==ID_pointer)
{
tmp.op1()=address_canonizer(tmp.op1(), ns);
return tmp;
}
else
return tmp;
}
else if(address.id()==ID_if)
{
if_exprt tmp=to_if_expr(address);
tmp.true_case()=address_canonizer(tmp.true_case(), ns);
tmp.false_case()=address_canonizer(tmp.false_case(), ns);
return tmp;
}
else if(address.id()==ID_typecast)
{
typecast_exprt tmp=to_typecast_expr(address);
// cast from another pointer?
if(tmp.op().type().id()==ID_pointer)
{
tmp.op()=address_canonizer(tmp.op(), ns);
return tmp;
}
return address;
}
else
return address;
}
void increment() { kernel_assert(!is_iterator()); _iteration_num++; }
size_t get_iteration_num() const { kernel_assert(!is_iterator()); return _iteration_num; }
Iterator *get_iterator() const { kernel_assert(is_iterator()); return _iterator; }
