public List <BaseBlock> sort()
{
var sorted = new Sorter(scopeBlock, scopeBlock.BaseBlocks, false).sort();
return(new ForwardScanOrder(scopeBlock, sorted).fix());
}
void Visit(BlockInfo info)
{
// This method used to be recursive but to prevent stack overflows,
// it's not recursive anymore.
var state = new VisitState(info);
recursive_call:
if (state.Info.baseBlock == firstBlock)
{
throw new ApplicationException("Can't visit firstBlock");
}
stack.Push(state.Info);
state.Info.onStack = true;
state.Info.dfsNumber = dfsNumber;
state.Info.low = dfsNumber;
dfsNumber++;
state.Targets = GetTargets(state.Info.baseBlock);
state.TargetIndex = 0;
return_to_caller:
for (; state.TargetIndex < state.Targets.Count; state.TargetIndex++)
{
state.TargetInfo = GetInfo(state.Targets[state.TargetIndex]);
if (state.TargetInfo == null)
{
continue;
}
if (state.TargetInfo.baseBlock == firstBlock)
{
continue;
}
if (!state.TargetInfo.Visited())
{
visitStateStack.Push(state);
state = new VisitState(state.TargetInfo);
goto recursive_call;
}
else if (state.TargetInfo.onStack)
{
state.Info.low = Math.Min(state.Info.low, state.TargetInfo.dfsNumber);
}
}
if (state.Info.low != state.Info.dfsNumber)
{
goto return_from_method;
}
var sccBlocks = new List <BaseBlock>();
while (true)
{
var poppedInfo = stack.Pop();
poppedInfo.onStack = false;
sccBlocks.Add(poppedInfo.baseBlock);
if (ReferenceEquals(state.Info, poppedInfo))
{
break;
}
}
if (sccBlocks.Count > 1)
{
sccBlocks.Reverse();
var result = new Sorter(scopeBlock, sccBlocks, true).Sort();
SortLoopBlock(result);
sorted.InsertRange(0, result);
}
else
{
sorted.Insert(0, sccBlocks[0]);
}
return_from_method:
if (visitStateStack.Count == 0)
{
return;
}
state = visitStateStack.Pop();
state.Info.low = Math.Min(state.Info.low, state.TargetInfo.low);
state.TargetIndex++;
goto return_to_caller;
}
void visit(BlockInfo info)
{
if (info.baseBlock == firstBlock)
{
throw new ApplicationException("Can't visit firstBlock");
}
stack.Push(info);
info.onStack = true;
info.dfsNumber = dfsNumber;
info.low = dfsNumber;
dfsNumber++;
foreach (var tmp in getTargets(info.baseBlock))
{
var targetInfo = getInfo(tmp);
if (targetInfo == null)
{
continue;
}
if (targetInfo.baseBlock == firstBlock)
{
continue;
}
if (!targetInfo.visited())
{
visit(targetInfo);
info.low = Math.Min(info.low, targetInfo.low);
}
else if (targetInfo.onStack)
{
info.low = Math.Min(info.low, targetInfo.dfsNumber);
}
}
if (info.low != info.dfsNumber)
{
return;
}
var sccBlocks = new List <BaseBlock>();
while (true)
{
var poppedInfo = stack.Pop();
poppedInfo.onStack = false;
sccBlocks.Add(poppedInfo.baseBlock);
if (ReferenceEquals(info, poppedInfo))
{
break;
}
}
if (sccBlocks.Count > 1)
{
sccBlocks.Reverse();
var result = new Sorter(scopeBlock, sccBlocks, true).sort();
sortLoopBlock(result);
sorted.InsertRange(0, result);
}
else
{
sorted.Insert(0, sccBlocks[0]);
}
}