private ParsedPragma ParseFor(List <List <Token> > lines, int startAddr, int currentLoopNum)
{
ParsedPragma result = new ParsedPragma();
List <ParsedInstruction> firstPassInstrs = new List <ParsedInstruction>();
int addr = startAddr;
for (int ln = 0; ln < lines.Count; ln++)
{
List <Token> line = lines[ln];
Token op = line[0];
if (op.Type == TokenType.OpCode)
{
if (mnemonicFormat.ContainsKey(op.Value))
{
MnemonicFormat instrFormat = mnemonicFormat[op.Value];
// Check if the number of operands is correct, remembering to
// account for the fact that the first token in the line was our
// opcode token
if (line.Count == instrFormat.OperandCount + 1)
{
ParsedInstruction parsedInstr = new ParsedInstruction(op.Value, op.LineNumber);
for (int i = 0; i < instrFormat.OperandCount; i++)
{
Token operand = line[i + 1];
if ((instrFormat.OperandTypes[i] & operand.Type) == operand.Type)
{
Operand o = new Operand(operand.Value, EnumConv.TokenToOperandType(operand.Type));
parsedInstr.Operands.Add(o);
}
}
firstPassInstrs.Add(parsedInstr);
addr += instrFormat.IWCount;
}
}
}
else if (op.Type == TokenType.Label)
{
labelLocations.Add(op.Value, addr);
}
else if (op.Type == TokenType.Pragma)
{
// We'll hardcode this for now but come back and make it general later
if (op.Value == "for" && line.Count == 5)
{
ParsedInstruction subInstr = new ParsedInstruction("sub", 0);
Token loopReg = line[1];
if (loopReg.Type != TokenType.RegName)
{
// Throw an error
throw new Exception("FOR loop token type mismatch - first argument not a register.");
}
// Subtract the register from itself to clear it
subInstr.Operands.Add(new Operand(loopReg.Value, OperandType.Register));
subInstr.Operands.Add(new Operand(loopReg.Value, OperandType.Register));
addr++; // SUB is one word long
ParsedInstruction addcInstr = new ParsedInstruction("addc", 0);
Token startVal = line[2];
if (startVal.Type != TokenType.Label && startVal.Type != TokenType.Constant)
{
if (startVal.Type == TokenType.RegName)
{
addcInstr = new ParsedInstruction("add", 0);
}
else
{
throw new Exception("FOR loop token type mismatch - second argument not a constant or label.");
}
}
addcInstr.Operands.Add(new Operand(loopReg.Value, OperandType.Register));
addcInstr.Operands.Add(new Operand(startVal.Value, EnumConv.TokenToOperandType(startVal.Type)));
addr++;
firstPassInstrs.Add(subInstr);
firstPassInstrs.Add(addcInstr);
int thisLoopNum = forLoopNum;
labelLocations.Add($"@@@FOR_LOOP_NUM_{thisLoopNum}", addr);
forLoopNum++;
List <List <Token> > restOfLines = new List <List <Token> >();
restOfLines.AddRange(lines.Skip(ln + 1));
ParsedPragma parsedFor = ParseFor(restOfLines, addr, thisLoopNum);
firstPassInstrs.AddRange(parsedFor.ParsedInstructions);
addr = parsedFor.NewAddrOffset;
ln += parsedFor.LinesParsed;
Operand regOp = new Operand(line[1].Value, EnumConv.TokenToOperandType(line[1].Type));
Operand startOp = new Operand(line[2].Value, EnumConv.TokenToOperandType(line[2].Type));
Operand loopOp = new Operand(line[3].Value, EnumConv.TokenToOperandType(line[3].Type));
Operand incOp = new Operand(line[4].Value, EnumConv.TokenToOperandType(line[4].Type));
List <ParsedInstruction> forInstrs = GenerateForCode(regOp, loopOp, incOp, thisLoopNum);
firstPassInstrs.AddRange(forInstrs);
addr += 10;
labelLocations.Add($"@@@END_FOR_LOOP_NUM_{thisLoopNum}", addr);
}
else if (op.Value == "endfor")
{
result.ParsedInstructions = firstPassInstrs;
result.NewAddrOffset = addr;
result.LinesParsed = ln + 1;
return(result);
}
}
}
throw new Exception("Error: endfor not detected to match start of FOR loop");
// throw new NotImplementedException();
}
private List <Operation> ParseCode(int startAddr = 0)
{
int addr = startAddr;
List <ParsedInstruction> firstPassInstrs = new List <ParsedInstruction>();
for (int ln = 0; ln < code.Count; ln++)
{
List <Token> line = code[ln];
Token op = line[0];
if (op.Type == TokenType.OpCode)
{
if (mnemonicFormat.ContainsKey(op.Value))
{
MnemonicFormat instrFormat = mnemonicFormat[op.Value];
// Check if the number of operands is correct, remembering to
// account for the fact that the first token in the line was our
// opcode token
if (line.Count == instrFormat.OperandCount + 1)
{
ParsedInstruction parsedInstr = new ParsedInstruction(op.Value, op.LineNumber);
for (int i = 0; i < instrFormat.OperandCount; i++)
{
Token operand = line[i + 1];
if ((instrFormat.OperandTypes[i] & operand.Type) == operand.Type)
{
Operand o = new Operand(operand.Value, EnumConv.TokenToOperandType(operand.Type));
parsedInstr.Operands.Add(o);
}
}
firstPassInstrs.Add(parsedInstr);
addr += instrFormat.IWCount;
}
else
{
throw new ParserException($"ERROR: Expected {instrFormat.OperandCount} parameters on line "
+ $"{op.LineNumber} for instruction {op.Value}. {line.Count - 1} parameters found.", op.LineNumber, line.Count);
}
}
else
{
throw new ParserException($"ERROR: Unknown mnemonic {op.Value} on line {op.LineNumber}.", op.LineNumber, 0);
}
}
else if (op.Type == TokenType.Label)
{
labelLocations.Add(op.Value, addr);
}
else if (op.Type == TokenType.Pragma)
{
// We'll hardcode this for now but come back and make it general later
if (op.Value == "for" && line.Count == 5)
{
ParsedInstruction subInstr = new ParsedInstruction("sub", 0);
Token loopReg = line[1];
if (loopReg.Type != TokenType.RegName)
{
// Throw an error
throw new Exception("FOR loop token type mismatch - first argument not a register.");
}
// Subtract the register from itself to clear it
subInstr.Operands.Add(new Operand(loopReg.Value, OperandType.Register));
subInstr.Operands.Add(new Operand(loopReg.Value, OperandType.Register));
addr++; // SUB is one word long
ParsedInstruction addcInstr = new ParsedInstruction("addc", 0);
Token startVal = line[2];
if (startVal.Type != TokenType.Label && startVal.Type != TokenType.Constant)
{
if (startVal.Type == TokenType.RegName)
{
addcInstr = new ParsedInstruction("add", 0);
}
else
{
throw new Exception("FOR loop token type mismatch - second argument not a constant or label.");
}
}
addcInstr.Operands.Add(new Operand(loopReg.Value, OperandType.Register));
addcInstr.Operands.Add(new Operand(startVal.Value, EnumConv.TokenToOperandType(startVal.Type)));
addr++;
firstPassInstrs.Add(subInstr);
firstPassInstrs.Add(addcInstr);
int currentLoopNum = forLoopNum;
labelLocations.Add($"@@@FOR_LOOP_NUM_{currentLoopNum}", addr);
forLoopNum++;
List <List <Token> > restOfLines = new List <List <Token> >();
restOfLines.AddRange(code.Skip(ln + 1));
ParsedPragma parsedFor = ParseFor(restOfLines, addr, currentLoopNum);
firstPassInstrs.AddRange(parsedFor.ParsedInstructions);
addr = parsedFor.NewAddrOffset;
ln += parsedFor.LinesParsed;
Operand regOp = new Operand(line[1].Value, EnumConv.TokenToOperandType(line[1].Type));
Operand startOp = new Operand(line[2].Value, EnumConv.TokenToOperandType(line[2].Type));
Operand loopOp = new Operand(line[3].Value, EnumConv.TokenToOperandType(line[3].Type));
Operand incOp = new Operand(line[4].Value, EnumConv.TokenToOperandType(line[4].Type));
List <ParsedInstruction> forInstrs = GenerateForCode(regOp, loopOp, incOp, currentLoopNum);
firstPassInstrs.AddRange(forInstrs);
addr += 10;
labelLocations.Add($"@@@END_FOR_LOOP_NUM_{currentLoopNum}", addr);
}
else if (op.Value != "for")
{
throw new ParserException($"ERROR: Unsupported pragma {op.Value} on line {op.LineNumber}.", op.LineNumber, 0);
}
else
{
throw new ParserException($"ERROR: Invalid number of arguments for FOR loop on line " +
$"{op.LineNumber}. Expected 4 arguments, received {line.Count - 1}.", op.LineNumber, 0);
}
}
else
{
throw new ParserException($"ERROR: Unsupported token type {op.Type} on line {op.LineNumber}.", op.LineNumber, 0);
}
}
List <Operation> parsedOps = new List <Operation>();
foreach (ParsedInstruction instr in firstPassInstrs)
{
Opcodes opName = EnumConv.StringToOpcode(instr.Name);
if (Operation.ManipOpcodes.Contains(opName))
{
int Ri = 0;
int Rj = 0;
// The Ri operand must always be a register, so we'll just
// check that and assign Ri easily
if (instr.Operands[0].Type != OperandType.Register)
{
throw new ParserException($"ERROR: Invalid Ri operand type {instr.Operands[0].Type} for instruction {instr.Name}.",
instr.LineNumber, 1);
}
Ri = int.Parse(instr.Operands[0].Value);
// Next we'll assign Rj, which can have a few types
// If Rj doesn't exist, it's fine, we can just keep it as 0.
// We have NOT which only takes one operand.
if (instr.Operands.Count > 1)
{
if (instr.Operands[1].Type == OperandType.Register || instr.Operands[1].Type == OperandType.Constant)
{
Rj = int.Parse(instr.Operands[1].Value);
}
else if (instr.Operands[1].Type == OperandType.Label)
{
if (dirDict.ContainsKey(instr.Operands[1].Value))
{
Rj = int.Parse(dirDict[instr.Operands[1].Value]);
}
else
{
throw new ParserException($"ERROR: Invalid label {instr.Operands[1].Value} on line {instr.LineNumber}.", instr.LineNumber, 2);
}
}
else
{
throw new ParserException($"ERROR: Invalid Rj operand type {instr.Operands[1].Type} for instruction {instr.Name}.",
instr.LineNumber, 2);
}
}
parsedOps.Add(new ManipulationOperation(Ri, Rj, opName));
}
else if (Operation.MemOpcodes.Contains(opName))
{
int Ri = 0;
int Rj = 0;
int offset = 0;
// Ri and Rj must be registers
Ri = int.Parse(instr.Operands[0].Value);
Rj = int.Parse(instr.Operands[1].Value);
// Offset can be a hard-coded or labeled constant
if (instr.Operands[2].Type == OperandType.Constant)
{
offset = int.Parse(instr.Operands[2].Value);
}
else if (instr.Operands[2].Type == OperandType.Label)
{
if (dirDict.ContainsKey(instr.Operands[2].Value))
{
offset = int.Parse(dirDict[instr.Operands[2].Value]);
}
else
{
throw new ParserException($"ERROR: Invalid label {instr.Operands[2].Value} on line {instr.LineNumber}.", instr.LineNumber, 3);
}
}
else
{
throw new ParserException($"ERROR: Invalid operand type {instr.Operands[2].Type} for instruction {instr.Name} on line {instr.LineNumber}.",
instr.LineNumber, 3);
}
parsedOps.Add(new MemoryOperation(Ri, Rj, offset, opName));
}
else if (Operation.MethodOpcodes.Contains(opName))
{
int offset = 0;
if (instr.Operands.Count > 0)
{
if (instr.Operands[0].Type == OperandType.Constant)
{
offset = int.Parse(instr.Operands[0].Value);
}
else if (instr.Operands[0].Type == OperandType.Label)
{
if (labelLocations.ContainsKey(instr.Operands[0].Value))
{
offset = labelLocations[instr.Operands[0].Value];
}
else
{
throw new ParserException($"ERROR: Invalid label {instr.Operands[0].Value} on line {instr.LineNumber}.", instr.LineNumber, 1);
}
}
else
{
throw new ParserException($"ERROR: Invalid operand type {instr.Operands[0].Type} for instruction {instr.Name} on line {instr.LineNumber}.",
instr.LineNumber, 1);
}
}
parsedOps.Add(new MethodOperation(offset, opName));
}
else if (Operation.StackOpcodes.Contains(opName))
{
int Ri = int.Parse(instr.Operands[0].Value);
parsedOps.Add(new StackOperation(Ri, opName));
}
else if (opName == Opcodes.JMP)
{
JumpTypes jmpType = EnumConv.StringToJumpType(instr.Name);
int offset = 0;
// This assembler will only allow direct AM, so Ri=0 and
// offset can be a constant or label
if (instr.Operands[0].Type == OperandType.Constant)
{
offset = int.Parse(instr.Operands[0].Value);
}
else if (instr.Operands[0].Type == OperandType.Label)
{
if (labelLocations.ContainsKey(instr.Operands[0].Value))
{
offset = labelLocations[instr.Operands[0].Value];
}
else
{
throw new ParserException($"ERROR: Invalid label {instr.Operands[0].Value} on line {instr.LineNumber}.", instr.LineNumber, 1);
}
}
else
{
throw new ParserException($"ERROR: Invalid operand type {instr.Operands[0].Type} for instruction {instr.Name} on line {instr.LineNumber}.",
instr.LineNumber, 1);
}
parsedOps.Add(new JumpOperation(0, offset, jmpType));
}
}
return(parsedOps);
}
