/**
* Return the smallest type that both t1 and t2 can be cast to without losing
* information.
*
* e.g.
*
* join_types(unsignedbv_typet(32), unsignedbv_typet(16))=unsignedbv_typet(32)
* join_types(signedbv_typet(16), unsignedbv_typet(16))=signedbv_typet(17)
* join_types(signedbv_typet(32), signedbv_typet(32))=signedbv_typet(32)
*/
typet join_types(const typet &t1, const typet &t2)
{
// Handle the simple case first...
if(t1==t2)
{
return t1;
}
// OK, they're not the same type. Are they both bitvectors?
if(is_bitvector(t1) && is_bitvector(t2))
{
// They are. That makes things easy! There are three cases to consider:
// both types are unsigned, both types are signed or there's one of each.
bitvector_typet b1=to_bitvector_type(t1);
bitvector_typet b2=to_bitvector_type(t2);
if(is_unsigned(b1) && is_unsigned(b2))
{
// We just need to take the max of their widths.
std::size_t width=std::max(b1.get_width(), b2.get_width());
return unsignedbv_typet(width);
}
else if(is_signed(b1) && is_signed(b2))
{
// Again, just need to take the max of the widths.
std::size_t width=std::max(b1.get_width(), b2.get_width());
return signedbv_typet(width);
}
else
{
// This is the (slightly) tricky case. If we have a signed and an
// unsigned type, we're going to return a signed type. And to cast
// an unsigned type to a signed type, we need the signed type to be
// at least one bit wider than the unsigned type we're casting from.
std::size_t signed_width=is_signed(t1) ? b1.get_width() :
b2.get_width();
std::size_t unsigned_width=is_signed(t1) ? b2.get_width() :
b1.get_width();
// unsigned_width++;
std::size_t width=std::max(signed_width, unsigned_width);
return signedbv_typet(width);
}
}
std::cerr << "Tried to join types: "
<< t1.pretty() << " and " << t2.pretty()
<< '\n';
assert(!"Couldn't join types");
}
bool languaget::from_type(
const typet &type,
std::string &code,
const namespacet &ns)
{
code=type.pretty();
return false;
}
void jsil_typecheckt::make_type_compatible(
exprt &expr,
const typet &type,
bool must)
{
if(type.id().empty() || type.is_nil())
{
err_location(expr);
error() << "make_type_compatible got empty type: " << expr.pretty() << eom;
throw 0;
}
if(expr.type().id().empty() || expr.type().is_nil())
{
// Type is not yet set
update_expr_type(expr, type);
return;
}
if(must)
{
if(jsil_incompatible_types(expr.type(), type))
{
err_location(expr);
error() << "failed to typecheck expr "
<< expr.pretty() << " with type "
<< expr.type().pretty()
<< "; required type " << type.pretty() << eom;
throw 0;
}
}
else if(!jsil_is_subtype(type, expr.type()))
{
// Types are not compatible
typet upper=jsil_union(expr.type(), type);
update_expr_type(expr, upper);
}
}
void cpp_typecheckt::typecheck_type(typet &type)
{
assert(!type.id().empty());
assert(type.is_not_nil());
try
{
cpp_convert_plain_type(type);
}
catch(const char *err)
{
error().source_location=type.source_location();
error() << err << eom;
throw 0;
}
catch(const std::string &err)
{
error().source_location=type.source_location();
error() << err << eom;
throw 0;
}
if(type.id()==ID_cpp_name)
{
c_qualifierst qualifiers(type);
cpp_namet cpp_name;
cpp_name.swap(type);
exprt symbol_expr=resolve(
cpp_name,
cpp_typecheck_resolvet::wantt::TYPE,
cpp_typecheck_fargst());
if(symbol_expr.id()!=ID_type)
{
error().source_location=type.source_location();
error() << "error: expected type" << eom;
throw 0;
}
type=symbol_expr.type();
assert(type.is_not_nil());
if(type.get_bool(ID_C_constant))
qualifiers.is_constant = true;
qualifiers.write(type);
}
else if(type.id()==ID_struct ||
type.id()==ID_union)
{
typecheck_compound_type(to_struct_union_type(type));
}
else if(type.id()==ID_pointer)
{
// the pointer might have a qualifier, but do subtype first
typecheck_type(type.subtype());
// Check if it is a pointer-to-member
if(type.find("to-member").is_not_nil())
{
// these can point either to data members or member functions
// of a class
typet &class_object=static_cast<typet &>(type.add("to-member"));
if(class_object.id()==ID_cpp_name)
{
assert(class_object.get_sub().back().id()=="::");
class_object.get_sub().pop_back();
}
typecheck_type(class_object);
// there may be parameters if this is a pointer to member function
if(type.subtype().id()==ID_code)
{
irept::subt ¶meters=type.subtype().add(ID_parameters).get_sub();
if(parameters.empty() ||
parameters.front().get(ID_C_base_name)!=ID_this)
{
// Add 'this' to the parameters
exprt a0(ID_parameter);
a0.set(ID_C_base_name, ID_this);
a0.type().id(ID_pointer);
a0.type().subtype() = class_object;
parameters.insert(parameters.begin(), a0);
}
}
}
}
else if(type.id()==ID_array)
{
exprt &size_expr=to_array_type(type).size();
if(size_expr.is_not_nil())
{
typecheck_expr(size_expr);
simplify(size_expr, *this);
}
typecheck_type(type.subtype());
if(type.subtype().get_bool(ID_C_constant))
type.set(ID_C_constant, true);
if(type.subtype().get_bool(ID_C_volatile))
type.set(ID_C_volatile, true);
}
else if(type.id()==ID_code)
{
code_typet &code_type=to_code_type(type);
typecheck_type(code_type.return_type());
code_typet::parameterst ¶meters=code_type.parameters();
for(auto ¶m : parameters)
{
typecheck_type(param.type());
// see if there is a default value
if(param.has_default_value())
{
typecheck_expr(param.default_value());
implicit_typecast(param.default_value(), param.type());
}
}
}
else if(type.id()==ID_template)
{
typecheck_type(type.subtype());
}
else if(type.id()==ID_c_enum)
{
typecheck_enum_type(type);
}
else if(type.id()==ID_c_enum_tag)
{
}
else if(type.id()==ID_c_bit_field)
{
typecheck_c_bit_field_type(to_c_bit_field_type(type));
}
else if(type.id()==ID_unsignedbv ||
type.id()==ID_signedbv ||
type.id()==ID_bool ||
type.id()==ID_floatbv ||
type.id()==ID_fixedbv ||
type.id()==ID_empty)
{
}
else if(type.id()==ID_symbol)
{
}
else if(type.id()==ID_constructor ||
type.id()==ID_destructor)
{
}
else if(type.id()=="cpp-cast-operator")
{
}
else if(type.id()=="cpp-template-type")
{
}
else if(type.id()==ID_typeof)
{
exprt e=static_cast<const exprt &>(type.find(ID_expr_arg));
if(e.is_nil())
{
typet tmp_type=
static_cast<const typet &>(type.find(ID_type_arg));
if(tmp_type.id()==ID_cpp_name)
{
// this may be ambiguous -- it can be either a type or
// an expression
cpp_typecheck_fargst fargs;
exprt symbol_expr=resolve(
to_cpp_name(static_cast<const irept &>(tmp_type)),
cpp_typecheck_resolvet::wantt::BOTH,
fargs);
type=symbol_expr.type();
}
else
{
typecheck_type(tmp_type);
type=tmp_type;
}
}
else
{
typecheck_expr(e);
type=e.type();
}
}
else if(type.id()==ID_decltype)
{
exprt e=static_cast<const exprt &>(type.find(ID_expr_arg));
typecheck_expr(e);
type=e.type();
}
else if(type.id()==ID_unassigned)
{
// ignore, for template parameter guessing
}
else if(type.id()==ID_template_class_instance)
{
// ok (internally generated)
}
else if(type.id()==ID_block_pointer)
{
// This is an Apple extension for lambda-like constructs.
// http://thirdcog.eu/pwcblocks/
}
else if(type.id()==ID_nullptr)
{
}
else
{
error().source_location=type.source_location();
error() << "unexpected cpp type: " << type.pretty() << eom;
throw 0;
}
assert(type.is_not_nil());
}
void cpp_typecheckt::typecheck_type(typet &type)
{
assert(type.id() != "");
assert(type.is_not_nil());
try
{
cpp_convert_plain_type(type);
}
catch(const char *error)
{
err_location(type);
str << error;
throw 0;
}
catch(const std::string &error)
{
err_location(type);
str << error;
throw 0;
}
if(type.id() == "cpp-name")
{
c_qualifierst qualifiers(type);
cpp_namet cpp_name;
cpp_name.swap(type);
exprt symbol_expr =
resolve(cpp_name, cpp_typecheck_resolvet::TYPE, cpp_typecheck_fargst());
if(symbol_expr.id() != "type")
{
err_location(type);
str << "error: expected type";
throw 0;
}
type = symbol_expr.type();
assert(type.is_not_nil());
if(type.cmt_constant())
qualifiers.is_constant = true;
qualifiers.write(type);
}
else if(type.id() == "struct" || type.id() == "union")
{
typecheck_compound_type(type);
}
else if(type.id() == "pointer")
{
// the pointer might have a qualifier, but do subtype first
typecheck_type(type.subtype());
// Check if it is a pointer-to-member
if(type.find("to-member").is_not_nil())
{
// these can point either to data members or member functions
// of a class
typet &class_object = static_cast<typet &>(type.add("to-member"));
if(class_object.id() == "cpp-name")
{
assert(class_object.get_sub().back().id() == "::");
class_object.get_sub().pop_back();
}
typecheck_type(class_object);
// there may be arguments if this is a pointer to member function
if(type.subtype().id() == "code")
{
irept::subt &args = type.subtype().add("arguments").get_sub();
if(args.empty() || args.front().cmt_base_name() != "this")
{
// Add 'this' to the arguments
exprt a0("argument");
a0.cmt_base_name("this");
a0.type().id("pointer");
a0.type().subtype() = class_object;
args.insert(args.begin(), a0);
}
}
}
// now do qualifier
if(type.find("#qualifier").is_not_nil())
{
typet &t = static_cast<typet &>(type.add("#qualifier"));
cpp_convert_plain_type(t);
c_qualifierst q(t);
q.write(type);
}
type.remove("#qualifier");
}
else if(type.id() == "array")
{
exprt &size_expr = to_array_type(type).size();
if(size_expr.is_nil())
type.id("incomplete_array");
else
typecheck_expr(size_expr);
// TODO: If is a incomplete_array, it should always
// have initializers, except for catch declaration
typecheck_type(type.subtype());
if(type.subtype().cmt_constant())
type.cmt_constant(true);
if(type.subtype().cmt_volatile())
type.set("#volatile", true);
}
else if(type.id() == "code")
{
code_typet &code_type = to_code_type(type);
typecheck_type(code_type.return_type());
code_typet::argumentst &arguments = code_type.arguments();
for(auto &argument : arguments)
{
typecheck_type(argument.type());
// see if there is a default value
if(argument.has_default_value())
{
typecheck_expr(argument.default_value());
implicit_typecast(argument.default_value(), argument.type());
}
}
}
else if(type.id() == "template")
{
typecheck_type(type.subtype());
}
else if(type.id() == "c_enum")
{
typecheck_enum_type(type);
}
else if(
type.id() == "unsignedbv" || type.id() == "signedbv" ||
type.id() == "bool" || type.id() == "floatbv" || type.id() == "fixedbv" ||
type.id() == "empty")
{
}
else if(type.id() == "symbol")
{
}
else if(type.id() == "constructor" || type.id() == "destructor")
{
}
else if(type.id() == "cpp-cast-operator")
{
}
else if(type.id() == "cpp-template-type")
{
}
else if(type.id() == "typeof")
{
exprt e = static_cast<const exprt &>(type.find("expr"));
if(e.is_nil())
{
typet tmp_type = static_cast<const typet &>(type.find("sizeof-type"));
if(tmp_type.id() == "cpp-name")
{
// this may be ambiguous -- it can be either a type or
// an expression
cpp_typecheck_fargst fargs;
exprt symbol_expr = resolve(
to_cpp_name(static_cast<const irept &>(tmp_type)),
cpp_typecheck_resolvet::BOTH,
fargs);
type = symbol_expr.type();
}
else
{
typecheck_type(tmp_type);
type = tmp_type;
}
}
else
{
typecheck_expr(e);
type = e.type();
}
}
else if(type.id() == "decltype")
{
exprt e = static_cast<const exprt &>(type.find("expr_arg"));
typecheck_expr(e);
type = e.type();
}
else if(type.id() == "unassigned")
{
// ignore, for template argument guessing
}
else if(type.id() == "ellipsis")
{
}
else
{
err_location(type);
str << "unexpected type: " << type.pretty();
throw 0;
}
assert(type.is_not_nil());
}
bool value_set_dereferencet::memory_model_bytes(
exprt &value,
const typet &to_type,
const guardt &guard,
const exprt &offset)
{
const typet from_type=value.type();
// We simply refuse to convert to/from code.
if(from_type.id()==ID_code || to_type.id()==ID_code)
return false;
// We won't do this without a commitment to an endianness.
if(config.ansi_c.endianness==configt::ansi_ct::endiannesst::NO_ENDIANNESS)
return false;
// But everything else we will try!
// We just rely on byte_extract to do the job!
exprt result;
// See if we have an array of bytes already,
// and we want something byte-sized.
if(ns.follow(from_type).id()==ID_array &&
pointer_offset_size(ns.follow(from_type).subtype(), ns)==1 &&
pointer_offset_size(to_type, ns)==1 &&
is_a_bv_type(ns.follow(from_type).subtype()) &&
is_a_bv_type(to_type))
{
// yes, can use 'index'
result=index_exprt(value, offset, ns.follow(from_type).subtype());
// possibly need to convert
if(!base_type_eq(result.type(), to_type, ns))
result.make_typecast(to_type);
}
else
{
// no, use 'byte_extract'
result=exprt(byte_extract_id(), to_type);
result.copy_to_operands(value, offset);
}
value=result;
// are we within the bounds?
if(options.get_bool_option("pointer-check"))
{
// upper bound
{
exprt from_width=size_of_expr(from_type, ns);
INVARIANT(
from_width.is_not_nil(),
"unknown or invalid type size:\n"+from_type.pretty());
exprt to_width=
to_type.id()==ID_empty?
from_integer(0, size_type()):size_of_expr(to_type, ns);
INVARIANT(
to_width.is_not_nil(),
"unknown or invalid type size:\n"+to_type.pretty());
INVARIANT(
from_width.type()==to_width.type(),
"type mismatch on result of size_of_expr");
minus_exprt bound(from_width, to_width);
if(bound.type()!=offset.type())
bound.make_typecast(offset.type());
binary_relation_exprt
offset_upper_bound(offset, ID_gt, bound);
guardt tmp_guard(guard);
tmp_guard.add(offset_upper_bound);
dereference_callback.dereference_failure(
"pointer dereference",
"object upper bound", tmp_guard);
}
// lower bound is easy
if(!offset.is_zero())
{
binary_relation_exprt
offset_lower_bound(
offset, ID_lt, from_integer(0, offset.type()));
guardt tmp_guard(guard);
tmp_guard.add(offset_lower_bound);
dereference_callback.dereference_failure(
"pointer dereference",
"object lower bound", tmp_guard);
}
}
return true;
}
bool base_type_eqt::base_type_eq_rec(
const typet &type1,
const typet &type2)
{
if(type1==type2)
return true;
#if 0
std::cout << "T1: " << type1.pretty() << std::endl;
std::cout << "T2: " << type2.pretty() << std::endl;
#endif
// loop avoidance
if((type1.id()==ID_symbol ||
type1.id()==ID_c_enum_tag ||
type1.id()==ID_struct_tag ||
type1.id()==ID_union_tag) &&
type2.id()==type1.id())
{
// already in same set?
if(identifiers.make_union(
type1.get(ID_identifier),
type2.get(ID_identifier)))
return true;
}
if(type1.id()==ID_symbol ||
type1.id()==ID_c_enum_tag ||
type1.id()==ID_struct_tag ||
type1.id()==ID_union_tag)
{
const symbolt &symbol=
ns.lookup(type1.get(ID_identifier));
if(!symbol.is_type)
return false;
return base_type_eq_rec(symbol.type, type2);
}
if(type2.id()==ID_symbol ||
type2.id()==ID_c_enum_tag ||
type2.id()==ID_struct_tag ||
type2.id()==ID_union_tag)
{
const symbolt &symbol=
ns.lookup(type2.get(ID_identifier));
if(!symbol.is_type)
return false;
return base_type_eq_rec(type1, symbol.type);
}
if(type1.id()!=type2.id())
return false;
if(type1.id()==ID_struct ||
type1.id()==ID_union)
{
const struct_union_typet::componentst &components1=
to_struct_union_type(type1).components();
const struct_union_typet::componentst &components2=
to_struct_union_type(type2).components();
if(components1.size()!=components2.size())
return false;
for(unsigned i=0; i<components1.size(); i++)
{
const typet &subtype1=components1[i].type();
const typet &subtype2=components2[i].type();
if(!base_type_eq_rec(subtype1, subtype2)) return false;
if(components1[i].get_name()!=components2[i].get_name()) return false;
}
return true;
}
else if(type1.id()==ID_incomplete_struct)
{
return true;
}
else if(type1.id()==ID_incomplete_union)
{
return true;
}
else if(type1.id()==ID_code)
{
const code_typet::parameterst ¶meters1=
to_code_type(type1).parameters();
const code_typet::parameterst ¶meters2=
to_code_type(type2).parameters();
if(parameters1.size()!=parameters2.size())
return false;
for(unsigned i=0; i<parameters1.size(); i++)
{
const typet &subtype1=parameters1[i].type();
const typet &subtype2=parameters2[i].type();
if(!base_type_eq_rec(subtype1, subtype2)) return false;
}
const typet &return_type1=to_code_type(type1).return_type();
const typet &return_type2=to_code_type(type2).return_type();
if(!base_type_eq_rec(return_type1, return_type2))
return false;
return true;
}
else if(type1.id()==ID_pointer)
{
return base_type_eq_rec(
to_pointer_type(type1).subtype(), to_pointer_type(type2).subtype());
}
else if(type1.id()==ID_array)
{
if(!base_type_eq_rec(
to_array_type(type1).subtype(), to_array_type(type2).subtype()))
return false;
if(to_array_type(type1).size()!=to_array_type(type2).size())
return false;
return true;
}
else if(type1.id()==ID_incomplete_array)
{
return base_type_eq_rec(
to_incomplete_array_type(type1).subtype(),
to_incomplete_array_type(type2).subtype());
}
// the below will go away
typet tmp1(type1), tmp2(type2);
base_type(tmp1, ns);
base_type(tmp2, ns);
return tmp1==tmp2;
}
