public static (ControlFlowGraph, string) Decompile(ControlFlowGraph graph /*, RecordFunc recordFunc = null*/)
{
if (graph == null)
{
throw new ArgumentNullException(nameof(graph));
}
var regions = graph.GetAllSeseRegions();
// Do smallest regions first, as they may be nested in a larger one
foreach (var(region, regionEntry, regionExit) in regions.OrderBy(x => x.nodes.Count))
{
if (regionEntry == graph.EntryIndex)
{
continue; // Don't try and reduce the 'sequence' of start node -> actual entry point nodes when there's only one entry
}
/* Func<string> vis = () => // For VS Code debug visualisation
* {
* var d = graph.ToVis();
* foreach(var n in d.Nodes)
* if (region.Contains(int.Parse(n.Id, CultureInfo.InvariantCulture)))
* n.Color = "#4040b0";
* return d.ToString();
* }; */
bool containsOther = regions.Any(x => x.nodes != region && !x.nodes.Except(region).Any());
if (containsOther)
{
continue;
}
// If either end is a loop header then leave it alone and let the loop rule handle it.
if (graph.GetBackEdges().Any(x => x.end == regionEntry || x.end == regionExit))
{
continue;
}
var cut = graph.Cut(region, regionEntry, regionExit);
if (cut.Cut.IsCyclic()) // Loop reduction comes later
{
continue;
}
return(cut.Merge(ReduceSese(cut.Cut)), Description);
}
return(graph, null);
}