public static ISet <Edge <BasicBlock> > FindReverseEdges(ControlFlowGraph.Graph g)
{
ISet <Edge <BasicBlock> > res = SetFactory.GetEdgesSet();//new SortedSet<Edge <BasicBlock>>();
Dictionary <Edge <BasicBlock>, EdgeType> ClassifiedEdges =
EdgeClassification.EdgeClassification.ClassifyEdge(g);
Dictionary <int, int> Dominators =
ImmediateDominator.FindImmediateDominator(g);
var RetreatingEdges = ClassifiedEdges.Where(x => x.Value == EdgeType.Retreating);
foreach (var edg in RetreatingEdges)
{
var edge = edg.Key;
int key = edge.Source.BlockId;
int value = edge.Target.BlockId;
bool isReverse = false;
while (Dominators.ContainsKey(key) && Dominators[key] != key && !isReverse)
{
key = Dominators[key];
isReverse = (key == value);
}
if (isReverse)
{
res.Add(edge);
}
}
return(res);
}
public static bool CheckReverseEdges(ControlFlowGraph.Graph g)
{
Dictionary <Edge <BasicBlock>, EdgeType> ClassifiedEdges = EdgeClassification.EdgeClassification.ClassifyEdge(g);
var RetreatingEdges = ClassifiedEdges.Where(x => x.Value == EdgeType.Retreating).Select(x => x.Key);
var ReverseEdges = FindReverseEdge.FindReverseEdges(g);
return(ReverseEdges.SetEquals(RetreatingEdges));
}
public static Dictionary <Edge <BasicBlock>, EdgeType> ClassifyEdge(ControlFlowGraph.Graph g)
{
Dictionary <Edge <BasicBlock>, EdgeType> edgeTypes = new Dictionary <Edge <BasicBlock>, EdgeType>();
Dictionary <int, int> dfn = g.GetDFN();
DominatorsTree tree = new DominatorsTree(g);
foreach (Edge <BasicBlock> e in g.GetEdges())
{
if (dfn[e.Source.BlockId] >= dfn[e.Target.BlockId])
{
edgeTypes.Add(e, EdgeType.Retreating);
}
else if (g.IsAncestor(e.Target.BlockId, e.Source.BlockId) && tree.GetParent(e.Target.BlockId) == e.Source.BlockId)
{
edgeTypes.Add(e, EdgeType.Advancing);
}
else
{
edgeTypes.Add(e, EdgeType.Cross);
}
}
return(edgeTypes);
}
public static Dictionary <Edge <BasicBlock>, ISet <int> > FindAllNaturalLoops(ControlFlowGraph.Graph g)
{
var classify = EdgeClassification.EdgeClassification.ClassifyEdge(g);
var result = new Dictionary <Edge <BasicBlock>, ISet <int> >();
foreach (var pair in classify)
{
if (pair.Value == EdgeClassification.Model.EdgeType.Retreating)
{
Stack = new Stack <int>();
Loop = SetFactory.GetSet(new int[] { pair.Key.Target.BlockId });
Insert(pair.Key.Source.BlockId);
while (Stack.Count() > 0)
{
int m = Stack.Pop();
foreach (BasicBlock p in g.getParents(m))
{
Insert(p.BlockId);
}
}
result.Add(pair.Key, Loop);
}
}
return(result);
}
