Cosmos/source2/Compiler/Cosmos.XSharp/Parser.cs
kudzu_cp c047b19781
2012-06-19 02:45:10 +00:00

250 lines
8.7 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Cosmos.Compiler.XSharp {
public class Parser {
protected int mStart = 0;
protected string mData;
protected bool mIncludeWhiteSpace;
protected bool mAllWhitespace;
protected bool mAllowPatterns;
protected TokenList mTokens;
public TokenList Tokens {
get { return mTokens; }
}
protected static readonly char[] mComma = ",".ToCharArray();
public static string[] mKeywords = (
"CALL"
+ ",END,EXIT"
+ ",GOTO,GROUP"
+ ",IF,INTERRUPTHANDLER"
+ ",JUMP"
+ ",POPALL,PUSHALL,PROCEDURE,PORT"
+ ",RETURN,RETURNINTERRUPT"
).Split(mComma);
public static readonly string[] Registers;
public static readonly string[] Registers8 = "AH,AL,BH,BL,CH,CL,DH,DL".Split(mComma);
public static readonly string[] Registers16 = "AX,BX,CX,DX".Split(mComma);
public static readonly string[] Registers32 = "EAX,EBX,ECX,EDX".Split(mComma);
public static readonly string[] RegistersIdx = "ESI,EDI,ESP,EBP".Split(mComma);
public static readonly string[] RegisterPatterns = "_REG,_REG8,_REG16,_REG32,_REGIDX".Split(mComma);
static Parser() {
var xRegisters = new List<string>();
xRegisters.AddRange(Registers8);
xRegisters.AddRange(Registers16);
xRegisters.AddRange(Registers32);
xRegisters.AddRange(RegistersIdx);
Registers = xRegisters.ToArray();
}
protected Token NewToken(ref int rPos) {
#region Pattern Notes
// All patterns start with _, this makes them reserved. User can use too, but at own risk of conflict.
//
// Wildcards
// -_REG or ??X
// -_REG8 or ?H,?L
// -_REG16 or ?X
// -_REG32 or E?X
// - ? based ones are ugly and less clear
// -_Keyword
// -_ABC
//
//
// Multiple Options (All caps only) - Registers only
// Used to suport EAX,EBX - ie lists. But found out wasnt really needed. May add again later.
//
// -AX/AL - Conflict if we ever use /
// -AX|AL - Conflict if we ever use |
// -AX,AL - , is unlikely to ever be used as an operator and is logical as a separator. Method calls might use, but likely better to use a space
// since we will only allow simple arguments, not compound.
// -_REG:AX|AL - End terminator issue
// -_REG[AX|AL] - Conflict with existing indirect access. Is indirect access always numeric? I think x86 has some register based ones too.
//
//
// Specific: Register, Keyword, AlphaNum
// -EAX
#endregion
string xString = null;
char xChar1 = mData[mStart];
var xToken = new Token();
if (mAllWhitespace && "#!".Contains(xChar1)) {
rPos = mData.Length; // This will account for the dummy whitespace at the end.
xString = mData.Substring(mStart + 1, rPos - mStart - 1).Trim();
if (xChar1 == '#') {
xToken.Type = TokenType.Comment;
} else if (xChar1 == '!') {
xToken.Type = TokenType.LiteralAsm;
}
} else {
xString = mData.Substring(mStart, rPos - mStart);
if (string.IsNullOrWhiteSpace(xString) && xString.Length > 0) {
xToken.Type = TokenType.WhiteSpace;
} else if (char.IsLetter(xChar1) || xChar1 == '_' || xChar1 == '.') {
string xUpper = xString.ToUpper();
if (mAllowPatterns) {
if (RegisterPatterns.Contains(xUpper)) {
xToken.Type = TokenType.Register;
} else if (xUpper == "_KEYWORD") {
xToken.Type = TokenType.Keyword;
xString = null;
} else if (xUpper == "_ABC") {
xToken.Type = TokenType.AlphaNum;
xString = null;
}
}
if (xToken.Type == TokenType.Unknown) {
if (Registers.Contains(xUpper)) {
xToken.Type = TokenType.Register;
} else if (mKeywords.Contains(xUpper)) {
xToken.Type = TokenType.Keyword;
} else {
xToken.Type = TokenType.AlphaNum;
}
}
} else if (char.IsDigit(xChar1)) {
xToken.Type = TokenType.ValueInt;
} else {
#region Symbols
if (xString == "[") {
xToken.Type = TokenType.BracketLeft;
} else if (xString == "]") {
xToken.Type = TokenType.BracketRight;
} else if (xString == "{") {
xToken.Type = TokenType.CurlyLeft;
} else if (xString == "}") {
xToken.Type = TokenType.CurlyRight;
} else if (xString == "+") {
xToken.Type = TokenType.Plus;
} else if (xString == "-") {
xToken.Type = TokenType.Minus;
} else if (xString == "=") {
xToken.Type = TokenType.Equals;
} else if (xString == ":") {
xToken.Type = TokenType.Colon;
} else if (xString == "$") {
xToken.Type = TokenType.Dollar;
} else if (xString == ",") {
xToken.Type = TokenType.Comma;
} else if (xString == "<") {
xToken.Type = TokenType.LessThan;
} else if (xString == ">") {
xToken.Type = TokenType.GreaterThan;
} else if (xString == "?") {
xToken.Type = TokenType.Question;
} else if (xString == "@") {
xToken.Type = TokenType.At;
}
#endregion
}
}
xToken.Value = xString;
xToken.SrcPosStart = mStart;
xToken.SrcPosEnd = rPos - 1;
if (mAllWhitespace && xToken.Type != TokenType.WhiteSpace) {
mAllWhitespace = false;
}
mStart = rPos;
return xToken;
}
protected enum CharType { WhiteSpace, Identifier, Symbol };
protected void Parse() {
var xTokens = ParseText();
mTokens = ParseTokens(xTokens);
}
// Rescan token patterns
protected TokenList ParseTokens(List<Token> aTokens) {
var xResult = new TokenList();
for (int i = 0; i < aTokens.Count; i++) {
int xRemainingTokens = aTokens.Count - i;
var xToken = aTokens[i];
if (xToken.Type == TokenType.WhiteSpace && mIncludeWhiteSpace == false) {
} else {
// $FF, $02, etc
if (xToken.Type == TokenType.Dollar && xRemainingTokens > 1) {
// Dont worry about whitespace, $ FF is not valid, $FF is.
var xNext = aTokens[i + 1];
if (xNext.Type == TokenType.ValueInt || xNext.Type == TokenType.AlphaNum) {
i++;
xToken.Type = TokenType.ValueInt;
xToken.SrcPosEnd = xNext.SrcPosEnd;
xToken.Value = "0x" + xNext.Value;
}
}
xResult.Add(xToken);
}
}
return xResult;
}
// Initial Parse to convert text to tokens
protected List<Token> ParseText() {
// Save in comment, might be useful in future. Already had to dig it out of TFS once
//var xRegex = new Regex(@"(\W)");
var xResult = new List<Token>();
char xLastChar = ' ';
CharType xLastCharType = CharType.WhiteSpace;
char xChar;
CharType xCharType = CharType.WhiteSpace;
int i = 0;
for (i = 0; i < mData.Length; i++) {
xChar = mData[i];
if (char.IsWhiteSpace(xChar)) {
xCharType = CharType.WhiteSpace;
} else if (char.IsLetterOrDigit(xChar) || xChar == '_' || xChar == '.') {
// _ and . were never likely to stand on their own. ie ESP _ 2 and ESP . 2 are never likely to be used.
// Having them on their own required a lot of code
// to treat them as a single unit where we did use them. So we treat them as AlphaNum.
xCharType = CharType.Identifier;
} else {
xCharType = CharType.Symbol;
}
// i > 0 - Never do NewToken on first char. i = 0 is just a pass to get char and set lastchar.
// But its faster as the second short circuit rather than a separate if.
if (xCharType != xLastCharType && i > 0) {
xResult.Add(NewToken(ref i));
}
xLastChar = xChar;
xLastCharType = xCharType;
}
// Last token
if (mStart < mData.Length) {
xResult.Add(NewToken(ref i));
}
return xResult;
}
public Parser(string aData, bool aIncludeWhiteSpace, bool aAllowPatterns) {
mData = aData;
mIncludeWhiteSpace = aIncludeWhiteSpace;
mAllowPatterns = aAllowPatterns;
mAllWhitespace = true;
Parse();
}
}
}