private void GenerateOperationLineASM(char opChar, string axReg, string tacWord)
{
TACFile.GetNextWord(); // skip operator
if (opChar == '+')
{
AssemblyFile.AddLine($" mov ax, {axReg}");
AssemblyFile.AddLine($" add ax, {GetAndFormatWord()}");
AssemblyFile.AddLine($" mov {tacWord}, ax");
}
else if (opChar == '-')
{
AssemblyFile.AddLine($" mov ax, {axReg}");
AssemblyFile.AddLine($" sub ax, {GetAndFormatWord()}");
AssemblyFile.AddLine($" mov {tacWord}, ax");
}
else if (opChar == '/')
{
AssemblyFile.AddLine($" mov ax, {axReg}");
AssemblyFile.AddLine($" cwd");
AssemblyFile.AddLine($" mov bx, {GetAndFormatWord()}");
AssemblyFile.AddLine($" idiv bx");
AssemblyFile.AddLine($" mov {tacWord}, ax");
}
else if (opChar == '*')
{
AssemblyFile.AddLine($" mov ax, {axReg}");
AssemblyFile.AddLine($" mov bx, {GetAndFormatWord()}");
AssemblyFile.AddLine($" imul bx");
AssemblyFile.AddLine($" mov {tacWord}, ax");
}
}
/// <summary>
/// WriteToken -> IdT | NumT | QuoteT
/// </summary>
private void WriteToken()
{
if (Token == Tokens.IdT)
{
ITableEntry entry = symbolTable.Lookup(Lexeme);
if (entry != null && entry.typeOfEntry == EntryType.varEntry)
{
tacGenerator.GenerateLineOfTAC($"wri {entry.bpOffsetName}");
}
else if (entry != null)
{
ErrorHandler.LogError($"only set up to handle integer variables");
}
else
{
ErrorHandler.LogError($"\"{Lexeme}\" is undeclared");
}
Match(Tokens.IdT);
}
else if (Token == Tokens.NumT)
{
tacGenerator.GenerateLineOfTAC($"wri {Lexeme}");
Match(Tokens.NumT);
}
else if (Token == Tokens.LiteralT)
{
tacGenerator.GenerateLineOfTAC($"wrs S{AssemblyFile.literalNum}");
AssemblyFile.AddLiteral(Lexeme);
Match(Tokens.LiteralT);
}
}
public void GenerateASMFile()
{
CurrentChar = ' ';
GenerateProgBeginningASM();
GenerateStartProcASM();
GenerateProcsASM();
AssemblyFile.AddLine("END start");
AssemblyFile.CreateASMFile();
}
private void GenerateStartProcASM()
{
AssemblyFile.AddLine("");
AssemblyFile.AddLine("start PROC");
AssemblyFile.AddLine(" mov ax, @data");
AssemblyFile.AddLine(" mov ds, ax");
AssemblyFile.AddLine($" call {AssemblyFile.mainName}");
AssemblyFile.AddLine(" mov ah, 04ch");
AssemblyFile.AddLine(" int 21h");
AssemblyFile.AddLine("start ENDP");
}
private void GenerateProgBeginningASM()
{
AssemblyFile.AddLine(" .model small");
AssemblyFile.AddLine(" .586");
AssemblyFile.AddLine(" .stack 100h");
AssemblyFile.AddLine(" .data");
AssemblyFile.AddLiteralsToASMFile();
AssemblyFile.AddLine(" .code");
AssemblyFile.AddLine(" include io.asm");
}
private void GenerateProcsASM()
{
Method proc = new Method();
while (ASMProcs.Count > 0)
{
proc = ASMProcs.Dequeue();
AssemblyFile.AddLine("");
AssemblyFile.AddLine($"{proc.lexeme} PROC");
AssemblyFile.AddLine(" push bp");
AssemblyFile.AddLine(" mov bp, sp");
AssemblyFile.AddLine($" sub sp, {proc.sizeOfLocalVars}");
GenerateProcBodyASM();
AssemblyFile.AddLine($" add sp, {proc.sizeOfLocalVars}");
AssemblyFile.AddLine(" pop bp");
AssemblyFile.AddLine($" ret {proc.sizeOfParameterVars - 4}");
AssemblyFile.AddLine($"{proc.lexeme} ENDP");
}
}
private void GenerateProcLineUsingVariableASM(string tacWord)
{
if (tacWord == "_ax")
{
TACFile.GetNextWord();
AssemblyFile.AddLine($" mov ax, {GetAndFormatWord()}");
}
else
{
TACFile.GetNextWord(); // skip equal sign
string axReg = GetAndFormatWord();
char opChar = TACFile.PeekNextChar();
if (opChar == '*' || opChar == '/' || opChar == '-' || opChar == '+')
{
GenerateOperationLineASM(opChar, axReg, tacWord);
}
else
{
GenerateAssignmentLineASM(axReg, tacWord);
}
}
}
private void GenerateProcLineUsingKeywordASM(string tacWord)
{
if (tacWord == "proc")
{
TACFile.GetNextWord();
}
else if (tacWord == "wrs")
{
AssemblyFile.AddLine($" mov dx, offset {TACFile.GetNextWord()}");
AssemblyFile.AddLine(" call writestr");
}
else if (tacWord == "wri")
{
string bpWord = GetAndFormatWord();
AssemblyFile.AddLine($" mov dx, {bpWord}");
AssemblyFile.AddLine($" call writeint");
}
else if (tacWord == "wrln")
{
AssemblyFile.AddLine($" call writeln");
}
else if (tacWord == "rdi")
{
string bpWord = GetAndFormatWord();
AssemblyFile.AddLine($" call readint");
AssemblyFile.AddLine($" mov {bpWord}, bx");
}
else if (tacWord == "call")
{
AssemblyFile.AddLine($" call {TACFile.GetNextWord()}");
}
else if (tacWord == "push")
{
AssemblyFile.AddLine($" mov ax, {GetAndFormatWord()}");
AssemblyFile.AddLine($" push ax");
}
}
private void GenerateAssignmentLineASM(string axReg, string tacWord)
{
if (axReg.Contains("ax"))
{
AssemblyFile.AddLine($" mov {tacWord}, ax");
}
else if (tacWord.Contains("ax"))
{
AssemblyFile.AddLine($" mov ax, {axReg}");
}
else
{
AssemblyFile.AddLine($" mov ax, {axReg}");
AssemblyFile.AddLine($" mov {tacWord}, ax");
if (!axReg.Contains("bp") && !int.TryParse(axReg, out int result))
{
tacWord = GetAndFormatWord();
TACFile.GetNextWord(); // skip equal sign
AssemblyFile.AddLine($" mov ax, {GetAndFormatWord()}");
AssemblyFile.AddLine($" mov {tacWord}, ax");
}
}
}