bool remove_function_pointerst::is_type_compatible(
bool return_value_used,
const code_typet &call_type,
const code_typet &function_type)
{
// we are willing to ignore anything that's returned
// if we call with 'void'
if(!return_value_used)
{
}
else if(type_eq(call_type.return_type(), empty_typet(), ns))
{
// ok
}
else
{
if(!arg_is_type_compatible(call_type.return_type(),
function_type.return_type()))
return false;
}
// let's look at the parameters
const code_typet::parameterst &call_parameters=call_type.parameters();
const code_typet::parameterst &function_parameters=function_type.parameters();
if(function_type.has_ellipsis() &&
function_parameters.empty())
{
// always ok
}
else if(call_type.has_ellipsis() &&
call_parameters.empty())
{
// always ok
}
else
{
// we are quite strict here, could be much more generous
if(call_parameters.size()!=function_parameters.size())
return false;
for(unsigned i=0; i<call_parameters.size(); i++)
if(!arg_is_type_compatible(call_parameters[i].type(),
function_parameters[i].type()))
return false;
}
return true;
}
bool cpp_typecheck_fargst::match(
const code_typet &code_type,
unsigned &distance,
cpp_typecheckt &cpp_typecheck) const
{
distance=0;
exprt::operandst ops = operands;
const code_typet::argumentst &arguments=code_type.arguments();
if(arguments.size()>ops.size())
{
// Check for default values.
ops.reserve(arguments.size());
for(unsigned i=ops.size(); i<arguments.size(); i++)
{
const exprt &default_value=
arguments[i].default_value();
if(default_value.is_nil())
return false;
ops.push_back(default_value);
}
}
else if(arguments.size()<ops.size())
{
// check for ellipsis
if(!code_type.has_ellipsis())
return false;
}
for(unsigned i=0; i<ops.size(); i++)
{
// read
// http://publib.boulder.ibm.com/infocenter/comphelp/v8v101/topic/com.ibm.xlcpp8a.doc/language/ref/implicit_conversion_sequences.htm
//
// The following are the three categories of conversion sequences in order from best to worst:
// * Standard conversion sequences
// * User-defined conversion sequences
// * Ellipsis conversion sequences
if(i>=arguments.size())
{
// Ellipsis is the 'worst' of the conversion sequences
distance+=1000;
continue;
}
exprt argument=arguments[i];
exprt &operand=ops[i];
#if 0
// unclear, todo
if(is_reference(operand.type()))
std::cout << "O: " << operand.pretty() << std::endl;
assert(!is_reference(operand.type()));
#endif
// "this" is a special case -- we turn the pointer type
// into a reference type to do the type matching
if(i==0 && argument.get("#base_name")==ID_this)
{
argument.type().set("#reference", true);
argument.type().set("#this", true);
}
unsigned rank = 0;
exprt new_expr;
#if 0
std::cout << "C: " << cpp_typecheck.to_string(operand.type())
<< " -> " << cpp_typecheck.to_string(argument.type()) << std::endl;
#endif
// can we do the standard conversion sequence?
if(cpp_typecheck.implicit_conversion_sequence(
operand, argument.type(), new_expr, rank))
{
// ok
distance+=rank;
#if 0
std::cout << "OK " << rank << std::endl;
#endif
}
else
{
#if 0
std::cout << "NOT OK" << std::endl;
#endif
return false; // no conversion possible
}
}
return true;
}
