public override void EnterInstruction([NotNull] CasmParser.InstructionContext context)
{
var instructionName = context?.NAME()?.GetText();
if (instructionName == null)
{
throw new InvalidOperationException("Could not find the opcode for the instruction.");
}
var operandTypes = new List <OperandType>();
var operands = new List <Operand>();
foreach (var expression in context.expressionList().expression())
{
if (expression.register() != null)
{
operandTypes.Add(OperandType.Register);
operands.Add(context.ExtractRegister(operands.Count));
}
else if (expression.registerReference() != null)
{
operandTypes.Add(OperandType.RegisterReference);
operands.Add(context.ExtractRegisterReference(operands.Count));
}
else if (expression.NUMBER() != null)
{
operandTypes.Add(OperandType.Immediate);
operands.Add(context.ExtractImmediate(operands.Count));
}
else if (expression.NAME() != null)
{
operandTypes.Add(OperandType.Label);
operands.Add(new ImmediateOperand(expression.NAME().GetText()));
}
}
if (InstructionMap.InstructionDefinitions.TryGetValue(new InstructionKey(instructionName, operandTypes.ToArray()), out var instructionDefinitions))
{
foreach (var instructionDefinition in instructionDefinitions)
{
_tree.AddNodes(new Instruction(_currentBytePosition, instructionDefinition, operands.ToArray()));
_currentBytePosition += 4;
}
return;
}
}
public static ImmediateOperand ExtractImmediate(this CasmParser.InstructionContext context, int operandPosition)
{
var immediateText = context.expressionList().expression(operandPosition).NUMBER().GetText().Replace("_", "");
uint value;
if (immediateText.Contains("0x") || immediateText.Contains("0X"))
{
value = Convert.ToUInt32(immediateText, 16);
}
else if (immediateText.Contains("0b") || immediateText.Contains("0B"))
{
value = Convert.ToUInt32(immediateText, 2);
}
else
{
value = uint.Parse(immediateText);
}
return(new ImmediateOperand(value));
}
public static RegisterOperand ExtractRegisterReference(this CasmParser.InstructionContext context, int operandPosition)
{
var registerText = context.expressionList().expression(operandPosition).registerReference().REGISTERREFERENCE().GetText();
return(new RegisterOperand(uint.Parse(RegisterReferenceRegex.Match(registerText).Groups[1].Value)));
}
public static RegisterOperand ExtractRegister(this CasmParser.InstructionContext context, int operandPosition)
{
var registerText = context.expressionList().expression(operandPosition).register().GetText();
return(new RegisterOperand(uint.Parse(registerText.Substring(1))));
}