// the argument value can be: int, double, String, DataElement
public static void check(Object argument, DataType parameter_datatype, AccessType parameter_accesstype)
{
// check if it is permitted to pass this variable
if (argument is DataElement)
{
DataElement e = (DataElement)argument;
DataType et = e.datatype;
if (et != parameter_datatype && parameter_datatype != DataType.Unspecified)
{
throw new AssemblerException("Using variable of wrong type for call: " + e.name);
}
}
// check in which cases a constant integer value is permitted
else if (argument is int)
{
int c = (int)argument;
if (parameter_accesstype == AccessType.ReadMany && parameter_datatype == DataType.I8)
{
throw new AssemblerException("Using constant value as parameter where a string value or variable reference is required");
}
if (parameter_accesstype != AccessType.Read)
{
throw new AssemblerException("Using constant value as parameter where a variable reference is required");
}
switch (parameter_datatype)
{
case DataType.I8:
if (c < -128 || c > 127)
{
throw new AssemblerException("Constant value " + c + "+ out of range of I8");
}
break;
case DataType.I16:
case DataType.VMThread:
if (c < -32768 || c > 32767)
{
throw new AssemblerException("Constant value " + c + "+ out of range of I16");
}
break;
case DataType.I32:
break; // must be implicitly in range
default:
throw new AssemblerException("Constant value " + c + " does not fit the parameter type " + parameter_datatype);
}
}
// check in which cases a constant float value is permitted
else if (argument is double)
{
if (parameter_datatype != DataType.F && parameter_datatype != DataType.Unspecified)
{
throw new AssemblerException("Can not use float literal '" + argument + "' for this parameter type");
}
if (parameter_accesstype != AccessType.Read)
{
throw new AssemblerException("Can not use float literal '" + argument + "' for output parameter");
}
}
// check in which cases a string literal is permitted
else if (argument is String)
{
if (parameter_datatype != DataType.I8)
{
throw new AssemblerException("Can not use string literal '" + argument + "' for this parameter type");
}
if (parameter_accesstype != AccessType.Read && parameter_accesstype != AccessType.ReadMany)
{
throw new AssemblerException("Can not use string literal '" + argument + "' for output parameter");
}
}
}
// decodes a parameter and adds it to bytecode stream.
// return either DataElement, int, double, or String (for type checking)
private Object DecodeAndAddParameter(DataArea locals, String p)
{
// this must be a label address difference
if ((!p.StartsWith("'")) && p.Contains(':'))
{
currentobject.AddLabelDifference(p);
return(999999999); // only compatible with 32bit numbers
}
// this must be a variable
else if ((p[0] >= 'A' && p[0] <= 'Z') || p[0] == '_')
{
// check if have offset suffix
int offset = 0;
int plusidx = p.IndexOf('+');
if (plusidx >= 0)
{
if (Int32.TryParse(p.Substring(plusidx + 1), NumberStyles.Integer, CultureInfo.InvariantCulture, out offset))
{
p = p.Substring(0, plusidx);
}
}
DataElement e = null;
bool local = true;
if (locals != null)
{
e = locals.Get(p);
}
if (e == null)
{
e = globals.Get(p);
local = false;
}
if (e == null)
{
throw new AssemblerException("Unknown identifier " + p);
}
currentobject.AddVariableReference(e.position + offset, local);
return(e);
}
// this must be a constant numeric value
else if ((p[0] >= '0' && p[0] <= '9') || p[0] == '-')
{
Int32 c;
double d;
if (Int32.TryParse(p, NumberStyles.Integer, CultureInfo.InvariantCulture, out c))
{
currentobject.AddConstant(c);
return(c);
}
if (double.TryParse(p, NumberStyles.Float, CultureInfo.InvariantCulture, out d))
{
currentobject.AddFloatConstant(d);
return(d);
}
throw new AssemblerException("Can not decode number: " + p);
}
// this must be a string literal
else if (p[0] == '\'')
{
String l = p.Substring(1, p.Length - 2);
currentobject.AddStringLiteral(l);
return(l);
}
else
{
throw new AssemblerException("Invalid parameter value");
}
}