// Parse Vars and Labels
bool Pass1()
{
Tokenizer.Token currentToken = tokenizer.GetNextToken();
if (currentToken.Type == Tokenizer.TokenType.Empty)
{
return(false);
}
int instrIdx = 0;
while (currentToken.Type != Tokenizer.TokenType.EOF && currentToken.Type != Tokenizer.TokenType.Unknown)
{
// ===================================================================
// Skip end of lines
if (currentToken.Type == Tokenizer.TokenType.EOL)
{
currentToken = tokenizer.GetNextToken();
}
// ===================================================================
// Parse variables
else if (currentToken.Type == Tokenizer.TokenType.Rsvd_Var)
{
currentToken = tokenizer.GetNextToken();
if (currentToken.Type == Tokenizer.TokenType.Ident)
{
if (!tables.AddVar(currentToken.Lexeme, scope, false))
{
errorHandler.ParserLogError("Var Already Exists");
return(false);
}
if (scope != -1)
{
if (!tables.FuncIncrementFrameSize(scope))
{
errorHandler.ParserLogError("Could not Find Function that Corresponds to Scope");
return(false);
}
}
}
else
{
errorHandler.ParserLogError("Ident Expected");
return(false);
}
currentToken = tokenizer.GetNextToken();
}
// ===================================================================
// Parse arguments
else if (currentToken.Type == Tokenizer.TokenType.Rsvd_Arg)
{
currentToken = tokenizer.GetNextToken();
if (currentToken.Type == Tokenizer.TokenType.Ident)
{
if (scope != -1)
{
if (!tables.AddVar(currentToken.Lexeme, scope, true))
{
errorHandler.ParserLogError("Arg Already Exists");
return(false);
}
if (!tables.FuncIncrementArgFrameSize(scope))
{
errorHandler.ParserLogError("Could not Find Function that Corresponds to Scope");
return(false);
}
}
else
{
errorHandler.ParserLogError("Declaring Arguments outside Functions is Illegal");
return(false);
}
}
else
{
errorHandler.ParserLogError("Ident Expected");
return(false);
}
currentToken = tokenizer.GetNextToken();
}
// ===================================================================
// Parse functions
else if (currentToken.Type == Tokenizer.TokenType.Rsvd_Func)
{
if (scope != -1)
{
errorHandler.ParserLogError("Declaring Functions in Functions is Illegal");
return(false);
}
currentToken = tokenizer.GetNextToken();
if (currentToken.Type == Tokenizer.TokenType.Ident)
{
if (!tables.AddFunc(currentToken.Lexeme, instrIdx, out scope))
{
errorHandler.ParserLogError("Function Already Exists");
return(false);
}
}
else
{
errorHandler.ParserLogError("Ident Expected");
return(false);
}
currentToken = tokenizer.GetNextToken();
}
else if (currentToken.Type == Tokenizer.TokenType.Rsvd_EndFunc)
{
scope = -1;
currentToken = tokenizer.GetNextToken();
}
// ===================================================================
// Parse instructions and labels
else if (currentToken.Type == Tokenizer.TokenType.Ident)
{
string ident = currentToken.Lexeme;
currentToken = tokenizer.GetNextToken();
// ===================================================================
// Is it a label?
if (currentToken.Type == Tokenizer.TokenType.Colon)
{
tables.AddLabel(ident, instrIdx, scope);
currentToken = tokenizer.GetNextToken();
}
// ===================================================================
// It's an instruction
else
{
if (scope == -1 && tables.GetStartPC() == -1)
{
tables.SetStartPC(instrIdx);
}
instrIdx++; // Increment counter
// Skip to next line
if (currentToken.Type != Tokenizer.TokenType.EOL)
{
currentToken = tokenizer.SkipToNextLine();
}
}
}
else
{
errorHandler.ParserLogError("Unexpected Token");
return(false);
}
}
return(true);
}
