MixByte GetFieldSpecValue(AssemblingStatus status, MixInstruction mixInstruction)
{
var fieldValue = mField.GetValue(status.LocationCounter);
switch (mixInstruction.MetaFieldSpec.Presence)
{
case MetaFieldSpec.Presences.Forbidden:
if (fieldValue == long.MinValue)
{
return(mixInstruction.FieldSpec.MixByteValue);
}
status.ReportParsingError(LineSection.AddressField, mFieldPartCharIndex, mTextLength - mFieldPartCharIndex, "fieldspec forbidden for this instruction");
return(null);
case MetaFieldSpec.Presences.Optional:
if (fieldValue == long.MinValue)
{
return(mixInstruction.MetaFieldSpec.DefaultFieldSpec.MixByteValue);
}
return((int)fieldValue);
case MetaFieldSpec.Presences.Mandatory:
if (fieldValue != long.MinValue)
{
return((int)fieldValue);
}
status.ReportParsingError(LineSection.AddressField, mFieldPartCharIndex, mTextLength - mFieldPartCharIndex, "fieldspec mandatory for this instruction");
return(null);
}
return(null);
}
bool AreValuesDefined(AssemblingStatus status)
{
if (!mAddress.IsValueDefined(status.LocationCounter))
{
status.ReportParsingError(LineSection.AddressField, 0, mIndexPartCharIndex, "address value undefined");
return(false);
}
if (!mIndex.IsValueDefined(status.LocationCounter))
{
status.ReportParsingError(LineSection.AddressField, mIndexPartCharIndex, mFieldPartCharIndex - mIndexPartCharIndex, "index value undefined");
return(false);
}
if (!mAddress.IsValueDefined(status.LocationCounter))
{
status.ReportParsingError(LineSection.AddressField, mFieldPartCharIndex, mTextLength - mFieldPartCharIndex, "field value undefined");
return(false);
}
return(true);
}
/// <summary>
/// Create a loader instruction instance with the parameters contained in this object.
/// </summary>
/// <param name="instruction">LoaderInstruction to create an instance of. This method will throw an exception if this parameter is of a different instruction type.</param>
/// <param name="status">AssemblingStatus object reflecting the current state of the assembly process</param>
/// <returns></returns>
public InstructionInstanceBase CreateInstance(InstructionBase instruction, AssemblingStatus status)
{
if (!(instruction is LoaderInstruction))
{
throw new ArgumentException("instruction must be a LoaderInstruction", nameof(instruction));
}
var loaderInstruction = (LoaderInstruction)instruction;
if (!mValue.IsValueDefined(status.LocationCounter))
{
status.ReportParsingError(LineSection.AddressField, 0, mTextLength, "value is not defined");
return(null);
}
return(new LoaderInstruction.Instance(loaderInstruction, mValue.GetSign(status.LocationCounter), mValue.GetMagnitude(status.LocationCounter)));
}
