public void SetValue(Romulus.StringSection name, LiteralValue value, bool isFixed, out Error error)
{
error = Error.None;
if (assembler.CurrentPass == null)
{
throw new InvalidOperationException("Can only access variables when assembler is running a pass.");
}
bool isDollar = Romulus.StringSection.Compare(name, "$", true) == 0;
if (isDollar)
{
assembler.CurrentPass.SetAddress(value.Value);
}
string nameString = name.ToString();
//assembler.CurrentPass.Values.Remove(nameString);
//assembler.CurrentPass.Values.Add(nameString, value);
bool fixedValueError;
assembler.CurrentPass.Values.SetValue(nameString, value, isFixed, out fixedValueError);
if (fixedValueError)
{
// Todo: replace this with assembler value, or return fixedValueError somehow.
//throw new Exception("Attempted to assign to a fixed value. This exception should be replaced with an appropriate assembler error.");
error = new Error(ErrorCode.Value_Already_Defined, string.Format(Error.Msg_ValueAlreadyDefined_name, nameString));
}
}
public ParsedInstruction(byte opcode, LiteralValue operandValue, int sourceLine)
{
this.opcode = opcode;
this.operandValue = operandValue;
this.operandExpression = null;
this.sourceLine = sourceLine;
}
public ParsedInstruction(byte opcode, string operandExpression, int sourceLine)
{
this.opcode = opcode;
this.operandValue = new LiteralValue();
this.operandExpression = operandExpression;
this.sourceLine = sourceLine;
}
public bool TryGetValue(Romulus.StringSection name, out LiteralValue result)
{
bool isDollar = Romulus.StringSection.Compare(name, "$", true) == 0;
if (isDollar)
{
result = new LiteralValue((ushort)assembler.CurrentPass.CurrentAddress, false);
return(true);
}
var value = assembler.CurrentPass.Values.TryGetValue(name.ToString());
result = value.HasValue ? value.Value : default(LiteralValue);
return(value.HasValue);
}
bool ParseOperand(StringSection operand, out LiteralValue value, out string expression)
{
if (ExpressionEvaluator.TryParseLiteral(operand, out value))
{
expression = null;
return(true);
}
else if (operand.Length > 0)
{
value = default(LiteralValue);
expression = operand.ToString();
return(true);
}
else
{
value = default(LiteralValue);
expression = null;
return(false);
}
}
public void SetValue(string name, LiteralValue value, bool isFixed, out bool valueIsFixedError)
{
PassValue existingValue;
bool exists = Values.TryGetValue(name, out existingValue);
if (exists)
{
if (existingValue.isFixed)
{
valueIsFixedError = true;
return;
}
else
{
Values.Remove(name);
}
}
Values.Add(name, new PassValue(value, isFixed));
valueIsFixedError = false;
}
private void EmitData(Pass pass, ref Error error, LiteralValue value)
{
switch (dataType)
{
case DataType.Bytes:
pass.CurrentAddress += 1;
pass.CurrentOutputOffset += 1;
if (pass.EmitOutput)
{
if (value.IsByte)
{
pass.WriteByte((byte)value.Value);
}
else
{
error = new Error(ErrorCode.Type_Mismatch, Error.Msg_ValueNotByte, SourceLine);
}
}
break;
case DataType.Words:
pass.CurrentAddress += 2;
pass.CurrentOutputOffset += 2;
if (pass.EmitOutput)
{
// if (value.IsByte) {
// error = new Error(ErrorCode.Type_Mismatch, Error.Msg_ValueNotWord, SourceLine);
//} else {
pass.WriteByte((byte)value.Value); // Low
pass.WriteByte((byte)(value.Value >> 8)); // High
//}
}
break;
case DataType.Implicit:
if (value.IsByte)
{
pass.CurrentAddress += 1;
pass.CurrentOutputOffset += 1;
if (pass.EmitOutput)
{
pass.WriteByte((byte)value.Value);
}
}
else
{
pass.CurrentAddress += 2;
pass.CurrentOutputOffset += 2;
if (pass.EmitOutput)
{
pass.WriteByte((byte)value.Value); // Low
pass.WriteByte((byte)(value.Value >> 8)); // High
}
}
break;
default:
System.Diagnostics.Debug.Fail("Invalid case");
break;
}
}
public AsmValue(string expression)
{
Literal = new LiteralValue();
Expression = expression;
}
public AsmValue(LiteralValue value)
{
this.Literal = value;
Expression = null;
}
public PassValue(LiteralValue value, bool isFixed)
{
this.value = value;
this.isFixed = isFixed;
}
private bool ParseInstruction(StringSection instruction, StringSection operand, int iSourceLine, out Error error)
{
error = Error.None;
if (operand.Length > 0 && operand[0] == '@')
{
}
var addressing = ParseAddressing(ref operand);
int opcodeVal = FindOpcode(instruction, addressing);
// Some instructions only support zero-page addressing variants of certain addressing modes
if ((OpcodeError)opcodeVal == OpcodeError.InvalidAddressing)
{
var newAddressing = addressing;
if (TryZeroPageEqivalent(ref newAddressing))
{
opcodeVal = FindOpcode(instruction, newAddressing);
if (opcodeVal >= 0)
{
addressing = newAddressing; // Keep the zero-page addressing
}
}
}
if (opcodeVal < 0)
{
// We don't throw an error if 'instruction' isn't an instruction (the line could be anything else other than instruction)
if ((OpcodeError)opcodeVal == OpcodeError.UnknownInstruction)
{
return(false);
}
else
{
SetOpcodeError(iSourceLine, instruction.ToString(), addressing, opcodeVal, out error);
return(true);
}
}
if (addressing != Opcode.addressing.implied)
{
LiteralValue operandValue = new LiteralValue();
string operandExpression = null;
// Todo: consider method(s) such as assembly.AddInstruction
if (ExpressionEvaluator.TryParseLiteral(operand, out operandValue))
{
assembly.ParsedInstructions.Add(new ParsedInstruction((byte)opcodeVal, operandValue, iSourceLine));
}
else if (operand.Length > 0)
{
assembly.ParsedInstructions.Add(new ParsedInstruction((byte)opcodeVal, operand.Trim().ToString(), iSourceLine));
}
else
{
assembly.ParsedInstructions.Add(new ParsedInstruction((byte)opcodeVal, default(LiteralValue), iSourceLine));
}
}
else
{
assembly.ParsedInstructions.Add(new ParsedInstruction((byte)opcodeVal, default(LiteralValue), iSourceLine));
}
return(true);
}
