bool OpcodeHandled(AsmState state, Line line)
{
var mnemonic = GetMnemonic(line);
var op = State.Cpu.FindOpcode(mnemonic);
if (op != null)
{
line.Address = state.Address;
State.Cpu.ParseOpcodeAndOperand(state, line, op);
return(true);
}
return(false);
}
bool StructHandled(AsmState state, Line line)
{
var structName = line.Opcode.Text;
var str = state.Symbols.GetStructs().FirstOrDefault(s => s.Text == structName);
if (str != null)
{
line.Address = state.Address;
var operands = line.Operand?.Text ?? "";
line.Length = str.ByteLength;
if (String.IsNullOrEmpty(operands))
{
Error(line, line.Opcode, "Empty struct operand");
return(false);
}
// odd special case of zeroed fields
var cleaned = operands.Replace("<", "").Replace(">", "").Replace("\t", "").Replace(" ", "");
var zeroOut = cleaned == "0"; // special case - if this, zero out structure
cleaned = ConvertStringsToNumbers(cleaned);
var items = cleaned.Split(',');
if (str.ByteLengths.Count != items.Length && !zeroOut)
{
Error(line, line.Operand, $"Struct def has {str.ByteLengths.Count} fields, operand has {items.Length}");
return(false);
}
var bytesAlready = line.Data.Count;
var value = 0;
for (var i = 0; i < str.ByteLengths.Count; ++i)
{
if (zeroOut || Evaluator.Evaluate(state, line, items[i], out value))
{
line.AddValue(value, str.ByteLengths[i]);
}
else
{
line.NeedsFixup = true;
var len = line.Data.Count;
if (len > bytesAlready) // restore state
{
line.Data.RemoveRange(bytesAlready, len - bytesAlready);
}
break; // will return to here and try again
}
}
return(true);
}
return(false);
}
bool PseudoOpHandled(AsmState state, Line line)
{
switch (line.Opcode.Text.ToLower())
{
case "fcc": // string data
line.Address = state.Address;
var num = ConvertStringsToNumbers(line.Operand.Text);
WriteData(state, line, num, 1);
break;
case "rmb": // reserve bytes
line.Address = state.Address;
var szText = line?.Operand?.Text ?? "";
if (ParseHex(szText, out var size))
{
line.Data.AddRange(new byte[size]);
line.Length = size;
line.Address += size;
}
else
{
state.Output.Error($"Cannot parse 'rmb' directive size {szText}");
}
break;
case "fcb": // byte data
line.Address = state.Address;
WriteData(state, line, line.Operand.Text, 1);
break;
case "fdb": // double byte data
line.Address = state.Address;
WriteData(state, line, line.Operand.Text, 2);
break;
case "end": // end of assembly
line.Address = state.Address;
line.Length = 0;
break;
default:
return(false);
}
return(true);
}
// write fdb or fcb data
void WriteData(AsmState state, Line line, string text, int itemLength)
{
var items = text.Split(',').Select(t => t.Trim()).ToList();
line.Length = itemLength * items.Count;
foreach (var item in items)
{
if (Evaluator.Evaluate(state, line, item, out int value))
{
line.AddValue(value, itemLength);
}
else
{
line.Data.Clear();
line.NeedsFixup = true;
break;
}
}
}
bool DirectiveHandled(AsmState state, Line line)
{
int value;
switch (line.Opcode.Text.ToLower())
{
case ".setdp": // set direct page
line.Address = state.Address;
line.Length = 0;
if (Evaluator.Evaluate(state, line, line.Operand.Text, out value))
{
state.dpRegister = value; // todo - move to CPU class
}
else
{
Error(line, line.Operand, "Cannot evaluate DP");
}
break;
case ".rom": // add rom definition
line.Address = state.Address;
line.Length = 0;
var fields = line.Operand.Text.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
.Select(r => r.Trim().ToLower())
.ToList();
if (fields.Count == 4 &&
Int32.TryParse(fields[1], out var size) &&
Int32.TryParse(fields[3],
NumberStyles.AllowHexSpecifier | NumberStyles.HexNumber, CultureInfo.InvariantCulture,
out var offset))
{
var filename = fields[0];
var sha1 = fields[2];
state.RomDefinitions.Add(new AsmState.RomDef(filename, size, offset, sha1));
}
else
{
Error(line, line.Operand, "Cannot parse .ROM directive.");
}
break;
case ".cpu": // set CPU type todo
case ".meta": // simple comment
line.Address = state.Address;
line.Length = 0;
break;
case "org":
case ".org": // set address
line.Address = state.Address;
line.Length = 0;
if (Evaluator.Evaluate(state, line, line.Operand.Text, out value))
{
state.Address = value;
}
else
{
Error(line, line.Operand, "Cannot evaluate address");
}
break;
default:
return(false);
}
return(true);
}
/// <summary>
/// Assemble the code.
/// Return true on no errors, else false
/// Inspect the State property to see returned items
/// </summary>
/// <param name="filename"></param>
/// <param name="textOut"></param>
/// <returns></returns>
public bool Assemble(string filename, TextWriter textOut)
{
State = new AsmState();
State.Output = new Output(textOut);
State.Output.Info("");
State.Output.Info("");
State.Output.Info($"Assembling file {filename}");
if (!File.Exists(filename))
{
State.Output.Error($"File {filename} does not exist.");
return(false);
}
State.Lines = Tokenizer.GetLines(File.ReadLines(filename), State.Output);
// determine CPU
foreach (var line in State.Lines)
{
if (line?.Opcode?.Text.ToLower() == ".cpu")
{
State.Cpu = MakeCpu(line?.Operand?.Text, State.Output);
}
}
if (State.Cpu == null)
{
State.Output.Info("CPU not detected, assuming 6809. Use '.cpu' directive to set.");
State.Cpu = new Cpu6809(false);
State.Cpu.Initialize(State.Output);
}
// clean all opcodes
foreach (var line in State.Lines)
{
if (line.Opcode != null)
{
line.Opcode.Text = State.Cpu.FixupMnemonic(line);
}
}
if (State.Lines == null)
{
return(false);
}
State.Output.Info($"{State.Lines.Count} lines tokenized.");
// handle #ifdef, #undef, etc
Preprocess();
//foreach (var line in lines)
// WriteLine(line.ToString());
// get structs, fill in sizes, validate
if (!MakeStructs())
{
return(false);
}
State.Output.Info($"{State.Symbols.GetStructs().Count} structs degrizzled.");
// foreach (var s in structs)
// WriteLine($"Struct {s}");
var labelLines = State.Lines.Where(d => d.Label != null);
foreach (var labelLine in labelLines)
{
State.Symbols.AddSymbol(new Label(labelLine), State.Output);
}
State.Output.Info($"{State.Symbols.Count} labels cryoambulated.");
if (!Assemble())
{
return(false);
}
return(CreateRom());
}