public JsStatement VisitGotoStateStatement(JsGotoStateStatement statement, object data)
{
var result = new List <JsStatement>();
State targetState;
if (statement.TargetState == null)
{
if (!_labelStates.TryGetValue(statement.TargetLabel, out targetState))
{
throw new InvalidOperationException("The label " + statement.TargetLabel + " does not exist.");
}
}
else
{
targetState = statement.TargetState.Value;
}
var remaining = statement.CurrentState.FinallyStack;
for (int i = 0, n = remaining.Count() - targetState.FinallyStack.Count(); i < n; i++)
{
var current = remaining.Peek();
remaining = remaining.Pop();
result.Add(JsExpression.Assign(JsExpression.Identifier(_stateVariableName), JsExpression.Number(remaining.IsEmpty ? -1 : remaining.Peek().Item1)));
result.Add(JsExpression.Invocation(JsExpression.Member(JsExpression.Identifier(current.Item2), "call"), JsExpression.This));
}
result.Add(MakeSetNextStateStatement(targetState.StateValue));
result.Add(targetState.StateValue == -1 ? (JsStatement)JsStatement.Break(targetState.LoopLabelName) : JsStatement.Continue(targetState.LoopLabelName));
return(JsStatement.BlockMerged(result));
}
private static JsStatement GenerateBody(string stateVariableName, List <Node> nodes)
{
if (nodes.Count == 0)
{
return(JsStatement.Break());
}
return(JsStatement.Switch(JsExpression.Identifier(stateVariableName),
nodes.Select(n => JsStatement.SwitchSection(n.StateValues.Select(v => JsExpression.Number(v)),
JsStatement.Try(
GenerateBody(stateVariableName, n.Children),
null,
JsExpression.Invocation(JsExpression.Member(JsExpression.Identifier(n.HandlerName), "call"), JsExpression.This))))));
}
private Tuple <List <JsStatement>, int> ProcessInner(JsBlockStatement statement, ImmutableStack <Tuple <string, State> > breakStack, ImmutableStack <Tuple <string, State> > continueStack, ImmutableStack <Tuple <int, string> > finallyStack, int?parentState)
{
var oldLoopLabel = _currentLoopLabel;
var oldRemainingBlocks = _remainingBlocks;
try {
_currentLoopLabel = _allocateLoopLabel();
_remainingBlocks = new Queue <RemainingBlock>();
_remainingBlocks.Enqueue(new RemainingBlock(ImmutableStack <StackEntry> .Empty.Push(new StackEntry(statement, 0)), breakStack, continueStack, CreateNewStateValue(finallyStack), new State(_currentLoopLabel, -1, finallyStack)));
if (_exitState == null)
{
_exitState = new State(_currentLoopLabel, -1, ImmutableStack <Tuple <int, string> > .Empty);
}
var sections = new List <Section>();
int iterationCount = 0;
while (_remainingBlocks.Count > 0)
{
var current = _remainingBlocks.Dequeue();
var list = Handle(current.Stack, current.BreakStack, current.ContinueStack, current.StateValue, current.ReturnState, _isIteratorBlock || _isAsync, true);
// Merge all top-level blocks that should be merged with their parents.
list = list.SelectMany(stmt => (stmt is JsBlockStatement && ((JsBlockStatement)stmt).MergeWithParent) ? ((JsBlockStatement)stmt).Statements : (IList <JsStatement>) new[] { stmt }).ToList();
sections.Add(new Section(current.StateValue, list));
if (iterationCount++ > 100000)
{
throw new Exception("Infinite loop when rewriting method to a state machine");
}
}
if (parentState != null && _isAsync)
{
List <int> childStates;
if (!_childStates.TryGetValue(parentState.Value, out childStates))
{
_childStates[parentState.Value] = childStates = new List <int>();
}
childStates.AddRange(sections.Select(s => s.State.StateValue));
}
var body = new List <JsStatement> {
JsStatement.Label(_currentLoopLabel,
JsStatement.For(JsStatement.Empty, null, null,
JsStatement.Switch(JsExpression.Identifier(_stateVariableName),
sections.Select(b => JsStatement.SwitchSection(
GetAllContainedStateValues(b.State.StateValue).OrderBy(v => v).Select(v => JsExpression.Number(v)),
JsStatement.Block(b.Statements)))
.Concat(new[] { JsStatement.SwitchSection(new JsExpression[] { null }, JsStatement.Break(_currentLoopLabel)) }))))
};
return(Tuple.Create(body, sections[0].State.StateValue));
}
finally {
_currentLoopLabel = oldLoopLabel;
_remainingBlocks = oldRemainingBlocks;
}
}
public void BreakStatementIsCorrectlyOutput()
{
AssertCorrect(JsStatement.Break(), "break;\n");
AssertCorrect(JsStatement.Break("someLabel"), "break someLabel;\n");
}
