void value_set_dereferencet::bounds_check(
const index_exprt &expr,
const guardt &guard)
{
if(!options.get_bool_option("pointer-check"))
return;
if(!options.get_bool_option("bounds-check"))
return;
const typet &array_type=ns.follow(expr.op0().type());
if(array_type.id()!=ID_array)
throw "bounds check expected array type";
std::string name=array_name(ns, expr.array());
{
mp_integer i;
if(!to_integer(expr.index(), i) &&
i>=0)
{
}
else
{
exprt zero=from_integer(0, expr.index().type());
if(zero.is_nil())
throw "no zero constant of index type "+
expr.index().type().pretty();
binary_relation_exprt
inequality(expr.index(), ID_lt, zero);
guardt tmp_guard(guard);
tmp_guard.add(inequality);
dereference_callback.dereference_failure(
"array bounds",
name+" lower bound", tmp_guard);
}
}
const exprt &size_expr=
to_array_type(array_type).size();
if(size_expr.id()==ID_infinity)
{
}
else if(size_expr.is_zero() && expr.array().id()==ID_member)
{
// this is a variable-sized struct field
}
else
{
if(size_expr.is_nil())
throw "index array operand of wrong type";
binary_relation_exprt inequality(expr.index(), ID_ge, size_expr);
if(c_implicit_typecast(
inequality.op0(),
inequality.op1().type(),
ns))
throw "index address of wrong type";
guardt tmp_guard(guard);
tmp_guard.add(inequality);
dereference_callback.dereference_failure(
"array bounds",
name+" upper bound", tmp_guard);
}
}
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)
