// TODO: replace this ugly-ass hack with proper AST support.
public Expression DecompileNew()
{
PopByte();
var parameters = new List<Expression>();
for (int n = 0; n < 5; n++)
{
if (CurrentIs(StandardByteCodes.Nothing))
{
parameters.Add(null);
continue;
}
var param = DecompileExpression();
if (param == null)
return null; // ERROR
parameters.Add(param);
}
Expression first = null;
if ((parameters[0] ?? parameters[1] ?? parameters[2]) != null)
{
var innerParms = new List<Expression>();
if (parameters[0] != null)
innerParms.Add(parameters[0]);
if (parameters[1] != null)
innerParms.Add(parameters[1]);
if (parameters[2] != null)
innerParms.Add(parameters[2]);
first = new FunctionCall(new SymbolReference(null, null, null, "new"), innerParms, null, null);
}
else {
first = new SymbolReference(null, null, null, "new");
}
var second = parameters[3] ?? new SymbolReference(null, null, null, "NoClass??");
var op = new InOpDeclaration("", 0, true, null, null, null, null, null, null, null);
var firstHalf = new InOpReference(op, first, second, null, null);
StartPositions.Pop();
if (parameters[4] != null)
return new InOpReference(op, firstHalf, parameters[4], null, null);
else
return firstHalf;
}
public Expression DecompileNativeFunction(UInt16 index)
{
var parameters = new List<Expression>();
while (!CurrentIs(StandardByteCodes.EndFunctionParms))
{
var param = DecompileExpression();
if (param == null)
return null; // ERROR
parameters.Add(param);
}
PopByte();
var entry = NativeTable[index];
Expression call = null;
switch (entry.Type)
{
case NativeType.Function:
var func = new SymbolReference(null, null, null, entry.Name);
call = new FunctionCall(func, parameters, null, null);
break;
case NativeType.Operator: // TODO: table should hold precedence, currently all have 0 and it'll be a mess.
var op = new InOpDeclaration(entry.Name, entry.Precedence, false, null, null, null, null, null, null, null);
call = new InOpReference(op, parameters[0], parameters[1], null, null);
break;
case NativeType.PreOperator: // TODO: table should hold precedence, currently all have 0 and it'll be a mess.
var preOp = new PreOpDeclaration(entry.Name, false, null, null, null, null, null, null);
call = new PreOpReference(preOp, parameters[0], null, null);
break;
case NativeType.PostOperator: // TODO: table should hold precedence, currently all have 0 and it'll be a mess.
var postOp = new PostOpDeclaration(entry.Name, false, null, null, null, null, null, null);
call = new PostOpReference(postOp, parameters[0], null, null);
break;
}
StartPositions.Pop();
return call;
}
public bool VisitNode(FunctionCall node)
{
throw new NotImplementedException();
}
public bool VisitNode(FunctionCall node)
{
ExpressionPrescedence.Push(NOPRESCEDENCE);
// functionName( parameter1, parameter2.. )
Append("{0}(", node.Function.Name);
foreach(Expression expr in node.Parameters)
{
expr.AcceptVisitor(this);
if (node.Parameters.IndexOf(expr) != node.Parameters.Count - 1)
Append(", ");
}
Append(")");
ExpressionPrescedence.Pop();
return true;
}
public Statement DecompileStatement()
{
StartPositions.Push((UInt16)Position);
var token = CurrentByte;
switch (token)
{
// return [expression];
case (byte)StandardByteCodes.Return:
return DecompileReturn();
// switch (expression)
case (byte)StandardByteCodes.Switch:
return DecompileSwitch();
// case expression :
case (byte)StandardByteCodes.Case:
return DecompileCase();
// if (expression) // while / for / do until
case (byte)StandardByteCodes.JumpIfNot:
return DecompileConditionalJump();
// continue
case (byte)StandardByteCodes.Jump: // TODO: UDK seems to compile this from break when inside ForEach, handle?
return DecompileJump();
// continue (iterator)
case (byte)StandardByteCodes.IteratorNext:
PopByte(); // pop iteratornext token
return DecompileJump();
// break;
case (byte)StandardByteCodes.IteratorPop:
return DecompileIteratorPop();
// stop;
case (byte)StandardByteCodes.Stop:
PopByte();
var stopStatement = new StopStatement(null, null);
StatementLocations.Add(StartPositions.Pop(), stopStatement);
return stopStatement;
// Goto label
case (byte)StandardByteCodes.GotoLabel:
PopByte();
var labelExpr = DecompileExpression();
var func = new SymbolReference(null, null, null, "goto");
var call = new FunctionCall(func, new List<Expression>() { labelExpr }, null, null);
var gotoLabel = new ExpressionOnlyStatement(null, null, call);
StatementLocations.Add(StartPositions.Pop(), gotoLabel);
return gotoLabel;
// assignable expression = expression;
case (byte)StandardByteCodes.Let:
case (byte)StandardByteCodes.LetBool:
case (byte)StandardByteCodes.LetDelegate:
return DecompileAssign();
// [skip x bytes]
case (byte)StandardByteCodes.Skip: // TODO: this should never occur as statement, possibly remove?
PopByte();
ReadUInt16();
StartPositions.Pop();
return DecompileStatement();
case (byte)StandardByteCodes.Nothing:
PopByte();
StartPositions.Pop();
return DecompileStatement(); // TODO, should probably have a nothing expression or statement, this is ugly
// foreach IteratorFunction(...)
case (byte)StandardByteCodes.Iterator:
return DecompileForEach();
// foreach arrayName(valuevariable[, indexvariable])
case (byte)StandardByteCodes.DynArrayIterator:
return DecompileForEach(isDynArray: true);
case (byte)StandardByteCodes.LabelTable:
DecompileLabelTable();
StartPositions.Pop();
return DecompileStatement();
#region unsupported
case (byte)StandardByteCodes.OptIfLocal: // TODO: verify, handle syntax
return DecompileConditionalJump(isOpt: true);
case (byte)StandardByteCodes.OptIfInstance: // TODO: verify, handle syntax
return DecompileConditionalJump(isOpt: true);
#endregion
default:
var expr = DecompileExpression();
if (expr != null)
{
var statement = new ExpressionOnlyStatement(null, null, expr);
StatementLocations.Add(StartPositions.Pop(), statement);
return statement;
}
// ERROR!
break;
}
return null;
}
// TODO: guess for loop, probably requires a large restructure
public Statement DecompileForEach(bool isDynArray = false)
{
PopByte();
var scopeStatements = new List<Statement>();
var iteratorFunc = DecompileExpression();
if (iteratorFunc == null)
return null;
Expression dynArrVar = null;
Expression dynArrIndex = null;
bool unknByte = false;
if (isDynArray)
{
dynArrVar = DecompileExpression();
unknByte = Convert.ToBoolean(ReadByte());
dynArrIndex = DecompileExpression();
}
var scopeEnd = ReadUInt16(); // MemOff
ForEachScopes.Push(scopeEnd);
Scopes.Add(scopeStatements);
CurrentScope.Push(Scopes.Count - 1);
while (Position < Size)
{
if (CurrentIs(StandardByteCodes.IteratorNext) && PeekByte == (byte)StandardByteCodes.IteratorPop)
{
PopByte(); // IteratorNext
PopByte(); // IteratorPop
break;
}
var current = DecompileStatement();
if (current == null)
return null; // ERROR ?
scopeStatements.Add(current);
}
CurrentScope.Pop();
ForEachScopes.Pop();
if (isDynArray)
{
var builder = new CodeBuilderVisitor(); // what a wonderful hack, TODO.
iteratorFunc.AcceptVisitor(builder);
var arrayName = new SymbolReference(null, null, null, builder.GetCodeString());
var parameters = new List<Expression>() { dynArrVar, dynArrIndex };
iteratorFunc = new FunctionCall(arrayName, parameters, null, null);
}
var statement = new ForEachLoop(iteratorFunc, new CodeBody(scopeStatements, null, null), null, null);
StatementLocations.Add(StartPositions.Pop(), statement);
return statement;
}