public void ReadInstruction(int line, bool section)
{
CurrentInstruction = section ? InputText[line] : InputData[line];
if (CurrentInstruction.Contains("#"))
{
CurrentInstruction = CurrentInstruction.Substring(0, CurrentInstruction.IndexOf("#"));
}
CurrentLine = line;
}
private bool assertRemoveComma()
{
if (CurrentInstruction.Length < 2 || CurrentInstruction.ElementAt(0) != ',')
{
gui.ReportError("Error: Comma expected");
return(false);
}
CurrentInstruction = CurrentInstruction.Substring(1);
return(true);
}
private bool FindRegister(int num)
{
bool foundRegister = false;
if (CurrentInstruction.ElementAt(0) != '$' || CurrentInstruction.Length < 2)
{
gui.ReportError("Error: Register expected");
return(foundRegister);
}
CurrentInstruction = CurrentInstruction.Substring(1);
string register = CurrentInstruction.Substring(0, 2);
if (register == "ze" && CurrentInstruction.Length >= 4)
{
register += CurrentInstruction.Substring(2, 2);
}
else if (register == "ze")
{
gui.ReportError("Error: Register expected");
return(foundRegister);
}
register = "$" + register;
for (int i = 0; i < Registers.Count; i++)
{
if (register == Registers[i].Label)
{
args[num] = i;
foundRegister = true;
if (i != 0)
{
CurrentInstruction = CurrentInstruction.Substring(2);
}
else
{
CurrentInstruction = CurrentInstruction.Substring(4);
}
}
}
if (!foundRegister)
{
gui.ReportError("Error: Invalid register");
}
return(foundRegister);
}
private int ParseInstruction()
{
int i = 0, j = 0; //temp vars
RemoveSpaces(CurrentInstruction);
if (CurrentInstruction.Contains(":"))
{
return(-2);
}
if (CurrentInstruction.Length < 4)
{
gui.ReportError("Error: Unknown operation");
return(-2);
}
for (j = 0; j < CurrentInstruction.Length; j++)
{
var temp = CurrentInstruction.ElementAt(j);
if (temp == ' ' || temp == '\t')
{
break;
}
}
string op = CurrentInstruction.Substring(0, j);
if (CurrentInstruction.Length > 0 && j < CurrentInstruction.Length - 1)
{
CurrentInstruction = CurrentInstruction.Substring(j + 1);
}
int OperationID = -1;
for (i = 0; i < InstructionSet.Length; i++)
{
if (op == InstructionSet[i])
{
OperationID = i;
break;
}
}
if (OperationID == -1)
{
gui.ReportError("Error:Unknown operation");
return(-2);
}
if (OperationID < 13) // R Format
{
for (int count = 0; count < 3 - (OperationID > 8 ? 1 : 0); count++)
{
RemoveSpaces(CurrentInstruction);
if (!FindRegister(count))
{
return(-2);
}
RemoveSpaces(CurrentInstruction);
if (count == 2 - (OperationID > 8 ? 1 : 0))
{
break;
}
if (!assertRemoveComma())
{
return(-2);
}
}
if (CurrentInstruction != "")
{
gui.ReportError("Error: Extra arguments provided");
return(-2);
}
}
else if (OperationID < 17) // I format
{
for (int count = 0; count < 2; count++)
{
RemoveSpaces(CurrentInstruction);
FindRegister(count);
RemoveSpaces(CurrentInstruction);
assertRemoveComma();
}
RemoveSpaces(CurrentInstruction);
string tempString = findLabel();
int temp;
if (!int.TryParse(tempString, out temp))
{
gui.ReportError("Error: Not a valid Immediate argument");
return(-2);
}
args[2] = temp;
}
else if (OperationID < 21) // lw sw ldc1 sdc1
{
string tempString = "";
int offset;
RemoveSpaces(CurrentInstruction);
FindRegister(0);
RemoveSpaces(CurrentInstruction);
assertRemoveComma();
RemoveSpaces(CurrentInstruction);
if ((CurrentInstruction.ElementAt(0) > 47 && CurrentInstruction.ElementAt(0) < 58) || CurrentInstruction.ElementAt(0) == '-')
{
j = 0;
while (j < CurrentInstruction.Length && CurrentInstruction.ElementAt(j) != ' ' &&
CurrentInstruction.ElementAt(j) != '\t' && CurrentInstruction.ElementAt(j) != '(')
{
tempString = tempString + CurrentInstruction.ElementAt(j);
j++;
}
if (j == CurrentInstruction.Length)
{
gui.ReportError("Error: '(' expected");
return(-2);
}
int temp;
if (!int.TryParse(tempString, out temp))
{
gui.ReportError("Error: not a valid offset");
return(-2);
}
offset = temp;
CurrentInstruction = CurrentInstruction.Substring(j);
RemoveSpaces(CurrentInstruction);
if (CurrentInstruction == "" || CurrentInstruction.ElementAt(0) != '(' || CurrentInstruction.Length < 2)
{
gui.ReportError("Error: '(' expected");
return(-2);
}
CurrentInstruction = CurrentInstruction.Substring(1);
RemoveSpaces(CurrentInstruction);
FindRegister(1);
RemoveSpaces(CurrentInstruction);
if (CurrentInstruction == "" || CurrentInstruction.ElementAt(0) != ')')
{
gui.ReportError("Error: ')' expected");
return(-2);
}
CurrentInstruction = CurrentInstruction.Substring(1);
OnlySpaces(0, CurrentInstruction.Length, CurrentInstruction);
args[2] = offset;
if (args[2] == -1)
{
gui.ReportError("Error: invalid offset");
return(-2);
}
}
else //label
{
tempString = findLabel();
bool foundLocation = false;
for (j = 0; j < MemoryTable.Count; j++)
{
if (tempString == MemoryTable[j].Label)
{
foundLocation = true;
args[1] = j;
break;
}
}
if (!foundLocation)
{
gui.ReportError("Error: invalid label");
return(-2);
}
args[2] = -1;
}
}
else if (OperationID < 23) // beq blt
{
for (int count = 0; count < 2; count++)
{
RemoveSpaces(CurrentInstruction);
FindRegister(count);
RemoveSpaces(CurrentInstruction);
assertRemoveComma();
}
RemoveSpaces(CurrentInstruction);
string tempString = findLabel();
bool found = false;
for (j = 0; j < LabelTable.Count; j++)
{
if (tempString == LabelTable[j].Label)
{
found = true;
args[2] = LabelTable[j].Address;
break;
}
}
if (!found)
{
gui.ReportError("Error: invalid label");
return(-2);
}
}
else if (OperationID < 26) // j bclt bclf
{
RemoveSpaces(CurrentInstruction);
bool found = false;
string tempString = findLabel();
for (j = 0; j < LabelTable.Count; j++)
{
if (tempString == LabelTable[j].Label)
{
found = true;
args[0] = LabelTable[j].Address;
}
}
if (!found)
{
gui.ReportError("Error: invalid label");
return(-2);
}
}
else if (OperationID < 28) // mflo mfhi
{
RemoveSpaces(CurrentInstruction);
if (!FindRegister(0))
{
return(-2);
}
if (!OnlySpaces(0, CurrentInstruction.Length, CurrentInstruction))
{
return(-2);
}
}
return(OperationID);
}