private void ParsePlusOrMinusLabel(ref StringSection line, char labelChar, int iInstruction, int iSourceLine)
{
int charCount = 1; // Number of times the label char (+ or -) appears
while (charCount < line.Length && line[charCount] == labelChar)
{
charCount++;
}
if (labelChar == '+')
{
assembly.AnonymousLabels.AddPlusLabel(charCount, iSourceLine);
}
else if (labelChar == '-')
{
assembly.AnonymousLabels.AddMinusLabel(charCount, iSourceLine);
}
else
{
throw new ArgumentException("Invalid label character for +/- label.", "labelChar");
}
assembly.TagAnonLabel(iInstruction, iSourceLine);
line = line.Substring(charCount).Trim();
// Remove colon if present
if (line.Length > 0 && line[0] == ':')
{
line = line.Substring(1).TrimLeft();
}
}
public void Process(StringSection source, List <StringSection> output, IFileSystem files)
{
bool moreLines = !source.IsNullOrEmpty;
while (moreLines)
{
int iLineBreak = source.IndexOfAny(lineBreaks);
StringSection line;
if (iLineBreak == -1)
{
// Last line
line = source;
source = StringSection.Empty;
moreLines = false;
}
else
{
line = source.Substring(0, iLineBreak);
bool isCRLF = (source[iLineBreak] == '\r') && (source.Length > iLineBreak + 1) && (source[iLineBreak + 1] == '\n');
if (isCRLF)
{
source = source.Substring(iLineBreak + 2);
}
else
{
source = source.Substring(iLineBreak + 1);
}
}
if (IsIncludeLine(line))
{
string includeFile = line.Substring(includeDirective.Length).Trim().ToString();
// Need to remove optional quotes
if (includeFile.Length >= 2 && includeFile[0] == '\"' && includeFile[includeFile.Length - 1] == '\"')
{
includeFile = includeFile.Substring(1, includeFile.Length - 2).Trim();
}
if (assembler.FileSystem.FileExists(includeFile))
{
ProcessInclude(output, files, includeFile);
}
else
{
assembler.AddError(new Error(ErrorCode.File_Error, string.Format(Error.Msg_FileNotFound_name, includeFile), output.Count));
}
}
else
{
output.Add(line);
}
}
}
private bool ParseNamedLabels(ref StringSection line, int iParsedLine, int iSourceLine)
{
int iColon = line.IndexOf(':');
if (iColon < 0)
{
return(false);
}
if ((line.Length - 1 > iColon) && (line[iColon + 1] == '='))
{
// := is not a label
return(false);
}
var labelName = line.Substring(0, iColon).Trim();
// Todo: should be able to validate via a 'parse symbol' func
// Check for nonzero length and that label starts with letter or @
if (labelName.Length == 0)
{
return(false);
}
if (!char.IsLetter(labelName[0]) && labelName[0] != '@')
{
return(false);
}
for (int i = 1; i < labelName.Length; i++) // i = 1 because we've already checked zero
{
if (!char.IsLetter(labelName[i]) && !char.IsDigit(labelName[i]) && labelName[i] != '_')
{
return(false);
}
}
if (labelName[0] == '@') // Local label
{
labelName = labelName.Substring(1); // Remove @
string fullName = mostRecentNamedLabel + "." + labelName.ToString(); // example: SomeFunction.LoopTop
assembly.Labels.Add(new Label(fullName, iParsedLine, iSourceLine, true));
}
else // Normal label
{
var sLabelName = labelName.ToString();
mostRecentNamedLabel = sLabelName;
assembly.Labels.Add(new Label(sLabelName, iParsedLine, iSourceLine, false));
}
line = line.Substring(iColon + 1).TrimLeft();
return(true);
}
/// <summary>
/// Returns a char array containing all the characters from a string. Escapes are processed. The specified string
/// should not include the opening quote. The parsed string will be removed from the string passed in. The closing
/// quote will not be removed, so that the caller can examine it and verify that there was a closing quote.
/// </summary>
/// <param name="section"></param>
/// <returns></returns>
public static char[] ParseString(ref StringSection str, out ErrorCode error)
{
error = ErrorCode.None;
// Only one thread can run this method at a time
lock (ParseLock) {
charBuilder.Clear();
while (str.Length > 0)
{
char c = str[0];
if (c == '\"')
{
return(charBuilder.ToArray());
}
else if (c == '\\')
{
str = str.Substring(1);
if (str.Length > 0)
{
c = str[0];
int escapeIndex = Array.IndexOf(escapeCodes, c);
if (escapeIndex < 0)
{
error = ErrorCode.Invalid_Escape;
return(null);
}
else
{
charBuilder.Add(escapeValues[escapeIndex]);
}
}
else
{
error = ErrorCode.Invalid_Escape;
return(null);
}
}
else
{
charBuilder.Add(c);
}
str = str.Substring(1);
}
return(charBuilder.ToArray());
}
}
/// <summary>
/// Returns a symbol name, or a zero-length string of no symbol was found.
/// </summary>
/// <param name="exp"></param>
/// <returns></returns>
private StringSection GetSymbol(StringSection exp)
{
// Check for special '$' variable
if (exp.Length > 0 && exp[0] == '$' && !char.IsLetter(exp[0]) && !char.IsDigit(exp[0]))
{
return("$");
}
if (exp.Length == 0)
{
return(StringSection.Empty);
}
if (!char.IsLetter(exp[0]) && exp[0] != '@')
{
return(StringSection.Empty);
}
int i = 1;
while (i < exp.Length)
{
char c = exp[i];
if (char.IsLetter(c) | char.IsDigit(c) | c == '_')
{
i++;
}
else
{
var result = exp.Substring(0, i);
return(result);
}
}
return(exp);
}
private void RemoveComments(ref StringSection line)
{
// ; denotes a comment, except within a string
bool inString = false;
for (int i = 0; i < line.Length; i++)
{
if (inString)
{
if (line[i] == '\"') // End of string
// unless it is preceeded by a backslash (then it's as escaped quote)
{
if (i == 0 || line[i - 1] != '\\')
{
inString = false;
}
}
}
else
{
if (line[i] == ';') // Comment
{
line = line.Substring(0, i);
return;
}
else if (line[i] == '\"') // Start of string
{
inString = true;
}
}
}
}
private static void StripComments(ref StringSection line)
{
int iComment = line.IndexOf(';');
if (iComment >= 0)
{
line = line.Substring(0, iComment);
}
line = line.Trim();
}
private StringSection ParseDirectiveName(StringSection text)
{
int i = 0;
while (i < text.Length && Char.IsLetter(text[i]))
{
i++;
}
return(text.Substring(0, i));
}
public IncBinDirective(int instructionIndex, int sourceLine, StringSection file)
: base(instructionIndex, sourceLine)
{
file = file.Trim();
if (file.Length > 1 && file[0] == '\"' && file[file.Length - 1] == '\"')
{
file = file.Substring(1, file.Length - 2);
}
this.Filename = file.ToString();
}
/// <summary>
/// Parses one anonymous label (both * and +/- types), if found, and removes it from the expression.
/// </summary>
/// <param name="line">The text to parse a label from. This text will be modified to remove the label.</param>
/// <param name="lineNumber">The index of the first instruction that follows the label.</param>
/// <param name="iSourceLine">The index of the source line the label occurs on.</param>
/// <returns>True if a label was parsed.</returns>
private bool ParseAnonymousLabel(ref StringSection line, int iInstruction, int iSourceLine)
{
// Todo: support named +/-/* labels. This means that the anon label collection will need to be able to store names.
if (line.Length > 0)
{
if (line[0] == '*')
{
assembly.AnonymousLabels.AddStarLabel(iSourceLine);
assembly.TagAnonLabel(iInstruction, iSourceLine);
line = line.Substring(1).TrimLeft();
// Remove colon if present
if (line.Length > 0 && line[0] == ':')
{
line = line.Substring(1).TrimLeft();
}
return(true);
}
else if (line[0] == '+' | line[0] == '-')
{
ParsePlusOrMinusLabel(ref line, line[0], iInstruction, iSourceLine);
return(true);
}
else if (line[0] == '{')
{
assembly.AnonymousLabels.AddLeftBraceLabel(iSourceLine);
assembly.TagAnonLabel(iInstruction, iSourceLine);
line = line.Substring(1).TrimLeft();
}
else if (line[0] == '}')
{
assembly.AnonymousLabels.AddRightBraceLabel(iSourceLine);
assembly.TagAnonLabel(iInstruction, iSourceLine);
line = line.Substring(1).TrimLeft();
}
}
return(false);
}
private bool IsIncludeLine(StringSection line)
{
if (line.Length < includeDirective.Length)
{
return(false);
}
var lineStart = line.Substring(0, includeDirective.Length);
if (StringSection.Compare(lineStart, includeDirective, true) == 0)
{
return(true);
}
return(false);
}
/// <summary>
/// Returns the addressing mode for the operand. Zero-page addressing modes are not considered (this can be addressed when omitting opcodes).
/// 'Accumulator' addressing is considered implied. The 'operand'
/// paremeter is updated to remove any addressing characters.
/// </summary>
/// <param name="operand">The operand string. Must be trimmed.</param>
/// <param name="addressing"></param>
/// <returns></returns>
private Opcode.addressing ParseAddressing(ref StringSection operand)
{
int opLen = operand.Length;
// Accumulator or implied
if (opLen == 0 || (opLen == 1 && Char.ToUpper(operand[0]) == 'A'))
{
return(Opcode.addressing.implied);
}
// Immediate
if (operand[0] == '#')
{
operand = operand.Substring(1).Trim();
return(Opcode.addressing.immediate);
}
// ,X
if (char.ToUpper(operand[opLen - 1]) == 'X')
{
var sansX = operand.Substring(0, opLen - 1).TrimRight();
if (sansX.Length > 0 && sansX[sansX.Length - 1] == ',')
{
sansX = sansX.Substring(0, sansX.Length - 1).Trim();
// Update operand to remove addressing
operand = sansX;
return(Opcode.addressing.absoluteIndexedX);
}
}
// (),Y
// ,Y
if (char.ToUpper(operand[opLen - 1]) == 'Y')
{
var sansY = operand.Substring(0, opLen - 1).TrimRight();
if (sansY.Length > 0 && sansY[sansY.Length - 1] == ',')
{
sansY = sansY.Substring(0, sansY.Length - 1).Trim();
//(),Y
if (sansY.Length > 0 && sansY[0] == '(' && sansY[sansY.Length - 1] == ')')
{
sansY = sansY.Substring(1, sansY.Length - 2).Trim();
operand = sansY;
return(Opcode.addressing.indirectY);
}
operand = sansY;
return(Opcode.addressing.absoluteIndexedY);
}
}
// ()
// (,X)
if (operand[0] == '(' && operand[opLen - 1] == ')')
{
operand = operand.Substring(1, opLen - 2).Trim();
opLen = operand.Length;
// (,X)
if (opLen > 0 && char.ToUpper(operand[opLen - 1]) == 'X')
{
var sansX = operand.Substring(0, opLen - 1).TrimRight();
if (sansX.Length > 0 && sansX[sansX.Length - 1] == ',')
{
sansX = sansX.Substring(0, sansX.Length - 1).Trim();
// Update operand to remove addressing
operand = sansX;
return(Opcode.addressing.indirectX);
}
}
return(Opcode.addressing.indirect);
}
////// ,x ,y () all require at least 3 chars
////if (opLen > 2) {
//// bool isIndexed = operand[operand.Length - 2] == ',';
//// char indexRegister = Char.ToUpper(operand[opLen - 1]);
//// if (isIndexed) {
//// if (indexRegister == 'X') {
//// operand = operand.Substring(0, opLen - 2);
//// return Opcode.addressing.absoluteIndexedX;
//// } else if (indexRegister == 'Y') {
//// bool isIndirect = operand[0] == '(' && operand.Length > 3 && operand[opLen - 3] == ')';
//// if (isIndirect) {
//// operand = operand.Substring(1, opLen - 4);
//// return Opcode.addressing.indirectY;
//// } else {
//// operand = operand.Substring(0, opLen - 2);
//// return Opcode.addressing.absoluteIndexedY;
//// }
//// }
//// }
//// bool is_Indirect = operand[0] == '(' && operand[opLen - 1] == ')';
//// if (is_Indirect) {
//// bool isXIndexed = opLen > 4 && operand[opLen - 3] == ',' && char.ToUpper(operand[opLen - 2]) == 'X';
//// if (isXIndexed) {
//// operand = operand.Substring(1, opLen - 4);
//// return Opcode.addressing.indirectX;
//// } else {
//// operand = operand.Substring(1, opLen - 2);
//// return Opcode.addressing.indirect;
//// }
//// }
////}
// If there are no addressing chars, it must be absolute (absolute vs. zero page is determined later)
return(Opcode.addressing.absolute);
}
/// <summary>
///
/// </summary>
/// <param name="line">The line of code to parse.</param>
/// <param name="sourceLine">The line number of the code file.</param>
void ParseLine(StringSection line, int iSourceLine, out Error error)
{
error = Error.None;
line = line.TrimLeft();
RemoveComments(ref line);
int newInstructionIndex = assembly.ParsedInstructions.Count;
bool loopLabel;
do // This loop allows us to parse alternating named and anonymous labels (* label: +++ -- anotherLabel:)
{
loopLabel = false;
loopLabel |= ParseNamedLabels(ref line, newInstructionIndex, iSourceLine);
loopLabel |= ParseAnonymousLabel(ref line, newInstructionIndex, iSourceLine);
} while (loopLabel);
if (line.IsNullOrEmpty || line[0] == ';')
{
// Nothing on this line
return;
}
// Dot-prefixed directive
if (line[0] == '.')
{
line = line.Substring(1);
var directiveName = GetSymbol(line);
line = line.Substring(directiveName.Length).TrimLeft();
if (!ParseDirective(directiveName, line, iSourceLine, out error))
{
error = new Error(ErrorCode.Directive_Not_Defined, string.Format(Error.Msg_DirectiveUndefined_name, directiveName), iSourceLine);
return;
}
return;
}
bool parsedUncolonedLabel = false; // Set to true when an uncoloned label is found so we don't look for one again.
bool loopAgain = false; // Set to true when an uncoloned label is found to loop back and try to parse the remaining text
do
{
loopAgain = false;
var symbol = GetSymbol(line);
if (symbol.Length == 0)
{
break;
}
line = line.Substring(symbol.Length).Trim();
if (ParseDirective(symbol, line, iSourceLine, out error))
{
return;
}
else if (ParseInstruction(symbol, line, iSourceLine, out error))
{
return;
}
else if ((line.Length > 0 && line[0] == '=') || (line.Length > 1 && line[0] == ':' && line[1] == '=')) // Assignments and label assignments
// := is a cross between a label and assignment: It declares a label with an explicit value.
{
bool isLabel = (line[0] == ':');
var expression = line.Substring(1).TrimLeft();
if (isLabel)
{
expression = expression.Substring(1).TrimLeft();
}
if (expression.IsNullOrEmpty)
{
error = new Error(ErrorCode.Expected_Expression, Error.Msg_ExpectedValue, iSourceLine);
}
else
{
ParseAssignment(symbol, isLabel, expression, iSourceLine);
}
}
else
{
// Todo: ensure 'symbol' is a valid label name
if (!Assembler.RequireColonOnLabels && !parsedUncolonedLabel && symbol.Length > 0)
{
if (symbol[0] == '@')
{
string labelName = mostRecentNamedLabel + "." + symbol.Substring(1).ToString();
assembly.Labels.Add(new Label(labelName, newInstructionIndex, iSourceLine, true));
}
else
{
mostRecentNamedLabel = symbol.ToString();
assembly.Labels.Add(new Label(symbol.ToString(), newInstructionIndex, iSourceLine, false));
}
parsedUncolonedLabel = true;
loopAgain = true;
}
else
{
error = new Error(ErrorCode.Unexpected_Text, Error.Msg_BadLine, iSourceLine);
}
}
} while (parsedUncolonedLabel && loopAgain);
}
/// <summary>
/// Returns true of a directive was parsed, even if it was not parsed successfully due to an error
/// </summary>
/// <param name="directiveName"></param>
/// <param name="line"></param>
/// <param name="sourceLine"></param>
/// <param name="error"></param>
/// <returns></returns>
private bool ParseDirective(StringSection directiveName, StringSection line, int sourceLine, out Error error)
{
error = Error.None;
if (StringEquals(directiveName, "org", true))
{
assembly.Directives.Add(new OrgDirective(NextInstructionIndex, sourceLine, new AsmValue(line.ToString())));
}
else if (StringEquals(directiveName, "base", true))
{
assembly.Directives.Add(new BaseDirective(NextInstructionIndex, sourceLine, new AsmValue(line.ToString())));
}
else if (StringEquals(directiveName, "incbin", true))
{
assembly.Directives.Add(new IncBinDirective(NextInstructionIndex, sourceLine, line));
}
else if (StringEquals(directiveName, "error", true))
{
assembly.Directives.Add(new ErrorDirective(NextInstructionIndex, sourceLine, line));
}
else if (StringEquals(directiveName, "patch", true))
{
assembly.Directives.Add(new PatchDirective(NextInstructionIndex, sourceLine, line.ToString()));
}
else if (StringEquals(directiveName, "define", true))
{
line = line.Trim();
if (GetSymbol(line).Length == line.Length) // line should contain a only a symbol
{
assembly.Directives.Add(new DefineDirective(NextInstructionIndex, sourceLine, line));
}
else
{
error = new Error(ErrorCode.Expected_LValue, string.Format(Error.Msg_InvalidSymbolName_name, line.ToString()), sourceLine);
}
}
else if (StringEquals(directiveName, "hex", true))
{
assembly.Directives.Add(new HexDirective(NextInstructionIndex, sourceLine, line));
}
else if (StringEquals(directiveName, "db", true))
{
assembly.Directives.Add(new DataDirective(NextInstructionIndex, sourceLine, line, DataDirective.DataType.Bytes));
}
else if (StringEquals(directiveName, "byte", true))
{
assembly.Directives.Add(new DataDirective(NextInstructionIndex, sourceLine, line, DataDirective.DataType.Bytes));
}
else if (StringEquals(directiveName, "dw", true))
{
assembly.Directives.Add(new DataDirective(NextInstructionIndex, sourceLine, line, DataDirective.DataType.Words));
}
else if (StringEquals(directiveName, "word", true))
{
assembly.Directives.Add(new DataDirective(NextInstructionIndex, sourceLine, line, DataDirective.DataType.Words));
}
else if (StringEquals(directiveName, "data", true))
{
assembly.Directives.Add(new DataDirective(NextInstructionIndex, sourceLine, line, DataDirective.DataType.Implicit));
}
else if (StringEquals(directiveName, "dsb", true))
{
assembly.Directives.Add(new StorageDirective(NextInstructionIndex, sourceLine, line, StorageDirective.DataType.Bytes));
}
else if (StringEquals(directiveName, "dsw", true))
{
assembly.Directives.Add(new StorageDirective(NextInstructionIndex, sourceLine, line, StorageDirective.DataType.Words));
}
else if (StringEquals(directiveName, "overflow", true))
{
assembly.Directives.Add(new OptionDirective(NextInstructionIndex, sourceLine, directiveName.ToString(), line.Trim().ToString()));
}
else if (StringEquals(directiveName, "if", true) ||
StringEquals(directiveName, "else", true) ||
StringEquals(directiveName, "ifdef", true) ||
StringEquals(directiveName, "ifndef", true) ||
StringEquals(directiveName, "endif", true))
{
assembly.Directives.Add(new ConditionalDirective(NextInstructionIndex, sourceLine, directiveName, line.Trim(), out error));
}
else if (StringEquals(directiveName, "ENUM", true))
{
assembly.Directives.Add(new EnumDirective(NextInstructionIndex, sourceLine, line));
}
else if (StringEquals(directiveName, "ENDE", true) || StringEquals(directiveName, "ENDENUM", true))
{
if (line.IsNullOrEmpty)
{
assembly.Directives.Add(new EndEnumDirective(NextInstructionIndex, sourceLine));
}
else
{
error = new Error(ErrorCode.Unexpected_Text, Error.Msg_NoTextExpected, sourceLine);
}
}
else if (StringEquals(directiveName, "signed", true))
{
assembly.Directives.Add(new OptionDirective(NextInstructionIndex, sourceLine, directiveName.ToString(), line.Trim().ToString()));
}
else if (StringEquals(directiveName, "needdot", true))
{
assembly.Directives.Add(new OptionDirective(NextInstructionIndex, sourceLine, directiveName.ToString(), line.Trim().ToString()));
}
else if (StringEquals(directiveName, "needcolon", true))
{
assembly.Directives.Add(new OptionDirective(NextInstructionIndex, sourceLine, directiveName.ToString(), line.Trim().ToString()));
}
else if (StringEquals(directiveName, "alias", true))
{
var varName = GetSymbol(line);
if (varName.IsNullOrEmpty)
{
error = new Error(ErrorCode.Syntax_Error, Error.Msg_ExpectedText, sourceLine);
return(true);
}
line = line.Substring(varName.Length).Trim();
assembly.Directives.Add(new Assignment(NextInstructionIndex, sourceLine, varName, true, new AsmValue(line.ToString())));
}
else
{
return(false);
}
return(true);
}
