private bool HandleTryStatement(JsTryStatement stmt, StackEntry location, ImmutableStack<StackEntry> stack, ImmutableStack<Tuple<string, State>> breakStack, ImmutableStack<Tuple<string, State>> continueStack, State currentState, State returnState, IList<JsStatement> currentBlock, bool isFirstStatement) {
if (_isIteratorBlock && (FindInterestingConstructsVisitor.Analyze(stmt.GuardedStatement, InterestingConstruct.YieldReturn) || (stmt.Finally != null && stmt.Catch == null && !currentState.FinallyStack.IsEmpty))) {
if (stmt.Catch != null)
throw new InvalidOperationException("Cannot yield return from try with catch");
string handlerName = _allocateFinallyHandler();
JsBlockStatement handler;
if (FindInterestingConstructsVisitor.Analyze(stmt.Finally, InterestingConstruct.Label)) {
var inner = ProcessInner(stmt.Finally, breakStack, continueStack, currentState.FinallyStack, currentState.StateValue);
handler = JsStatement.Block(new[] { new JsSetNextStateStatement(inner.Item2) }.Concat(inner.Item1));
handler = new FinalizerRewriter(_stateVariableName, _labelStates).Process(handler);
}
else {
handler = stmt.Finally;
}
_finallyHandlers.Add(Tuple.Create(handlerName, handler));
var stateAfter = GetStateAfterStatement(location, stack, currentState.FinallyStack, returnState);
var innerState = CreateNewStateValue(currentState.FinallyStack, handlerName);
var stateBeforeFinally = CreateNewStateValue(innerState.FinallyStack);
currentBlock.Add(new JsSetNextStateStatement(innerState.StateValue));
currentBlock.AddRange(Handle(ImmutableStack<StackEntry>.Empty.Push(new StackEntry(stmt.GuardedStatement, 0)), breakStack, continueStack, new State(currentState.LoopLabelName, currentState.StateValue, innerState.FinallyStack), stateBeforeFinally, false, false));
Enqueue(ImmutableStack<StackEntry>.Empty.Push(new StackEntry(JsStatement.Block(JsStatement.BlockMerged(new JsStatement[0])), 0)), breakStack, continueStack, stateBeforeFinally, stateAfter.Item1);
if (!stack.IsEmpty || location.Index < location.Block.Statements.Count - 1) {
Enqueue(PushFollowing(stack, location), breakStack, continueStack, stateAfter.Item1, returnState);
}
return false;
}
else if (_isIteratorBlock && stmt.Finally != null && !currentState.FinallyStack.IsEmpty) {
// This is necessary to special-case in order to ensure that the inner finally block is executed before all outer ones.
return HandleTryStatement(JsStatement.Try(JsStatement.Try(stmt.GuardedStatement, stmt.Catch, null), null, stmt.Finally), location, stack, breakStack, continueStack, currentState, returnState, currentBlock, isFirstStatement);
}
else {
var rewriter = new NestedStatementFixer(breakStack, continueStack, currentState, _exitState.Value, _makeSetResult);
JsBlockStatement guarded;
var guardedConstructs = FindInterestingConstructsVisitor.Analyze(stmt.GuardedStatement);
if ((guardedConstructs & (InterestingConstruct.Label | InterestingConstruct.Await)) != InterestingConstruct.None) {
if (!isFirstStatement) {
var sv = CreateNewStateValue(currentState.FinallyStack);
Enqueue(stack.Push(location), breakStack, continueStack, sv, returnState);
currentBlock.Add(new JsGotoStateStatement(sv, currentState));
return false;
}
var inner = ProcessInner(stmt.GuardedStatement, breakStack, continueStack, currentState.FinallyStack, currentState.StateValue);
guarded = JsStatement.Block(inner.Item1);
currentBlock.Add(new JsSetNextStateStatement(inner.Item2));
}
else {
guarded = rewriter.Process(stmt.GuardedStatement);
}
JsCatchClause @catch;
if (stmt.Catch != null) {
if (FindInterestingConstructsVisitor.Analyze(stmt.Catch.Body, InterestingConstruct.Label)) {
var inner = ProcessInner(stmt.Catch.Body, breakStack, continueStack, currentState.FinallyStack, null);
@catch = JsStatement.Catch(stmt.Catch.Identifier, JsStatement.Block(new[] { new JsSetNextStateStatement(inner.Item2) }.Concat(inner.Item1)));
}
else {
var body = rewriter.Process(stmt.Catch.Body);
@catch = ReferenceEquals(body, stmt.Catch.Body) ? stmt.Catch : JsStatement.Catch(stmt.Catch.Identifier, body);
}
}
else
@catch = null;
JsBlockStatement @finally;
if (stmt.Finally != null) {
if (FindInterestingConstructsVisitor.Analyze(stmt.Finally, InterestingConstruct.Label)) {
var inner = ProcessInner(stmt.Finally, breakStack, continueStack, currentState.FinallyStack, null);
@finally = JsStatement.Block(new[] { new JsSetNextStateStatement(inner.Item2) }.Concat(inner.Item1));
}
else
@finally = rewriter.Process(stmt.Finally);
if ((guardedConstructs & InterestingConstruct.Await) != InterestingConstruct.None) {
// Wrap the finally block inside an 'if (doFinallyBlocks) {}'
@finally = JsStatement.Block(JsStatement.If(JsExpression.Identifier(_doFinallyBlocksVariableName), @finally, null));
}
}
else
@finally = null;
if (currentBlock.Count > 0 && _childStates.ContainsKey(currentState.StateValue)) {
var newBlock = JsStatement.If(JsExpression.Same(JsExpression.Identifier(_stateVariableName), JsExpression.Number(currentState.StateValue)), JsStatement.Block(currentBlock), null);
currentBlock.Clear();
currentBlock.Add(newBlock);
}
currentBlock.Add(JsStatement.Try(guarded, @catch, @finally));
return true;
}
}
private JsBlockStatement Process(JsBlockStatement statement, bool isIteratorBlock)
{
_stateVariableName = _allocateStateVariable();
_nextStateIndex = 0;
_isIteratorBlock = isIteratorBlock;
_processedStates = new HashSet<State>();
_labelStates = new Dictionary<string, State>();
_finallyHandlers = new List<Tuple<string, JsBlockStatement>>();
_allStates = new List<State>();
_remainingBlocks = new Queue<RemainingBlock>();
_exitState = null;
var body = ProcessInner(statement, ImmutableStack<Tuple<string, State>>.Empty, ImmutableStack<Tuple<string, State>>.Empty, ImmutableStack<Tuple<int, string>>.Empty);
body.RemoveAt(0); // Remove the initial assignment of the state. This will instead happen in the statement that declares the variables for this state machine.
if (_isIteratorBlock)
body.Add(new JsReturnStatement(JsExpression.False));
var resultBody = new FinalizerRewriter(_stateVariableName, _labelStates).Process(new JsBlockStatement(body));
return resultBody;
}
private JsBlockStatement Process(JsBlockStatement statement, bool isIteratorBlock, bool isAsync) {
_stateVariableName = _allocateStateVariable();
_nextStateIndex = 0;
_isIteratorBlock = isIteratorBlock;
_isAsync = isAsync;
_processedStates = new HashSet<State>();
_labelStates = new Dictionary<string, State>();
_finallyHandlers = new List<Tuple<string, JsBlockStatement>>();
_allStates = new List<State>();
_remainingBlocks = new Queue<RemainingBlock>();
_exitState = null;
_childStates = new Dictionary<int, List<int>>();
var body = ProcessInner(statement, ImmutableStack<Tuple<string, State>>.Empty, ImmutableStack<Tuple<string, State>>.Empty, ImmutableStack<Tuple<int, string>>.Empty, null).Item1;
if (_isIteratorBlock)
body.Add(JsStatement.Return(JsExpression.False));
var resultBody = new FinalizerRewriter(_stateVariableName, _labelStates).Process(JsStatement.Block(body));
return resultBody;
}
