internal ControlFlowGraph(ControlFlowNode[] nodes)
{
this.nodes = new ReadOnlyCollection<ControlFlowNode>(nodes);
Debug.Assert(EntryPoint.NodeType == ControlFlowNodeType.EntryPoint);
Debug.Assert(RegularExit.NodeType == ControlFlowNodeType.RegularExit);
Debug.Assert(ExceptionalExit.NodeType == ControlFlowNodeType.ExceptionalExit);
}
/// <summary>
/// Gets whether <c>this</c> dominates <paramref name="node"/>.
/// </summary>
public bool Dominates(ControlFlowNode node)
{
// TODO: this can be made O(1) by numbering the dominator tree
ControlFlowNode tmp = node;
while (tmp != null) {
if (tmp == this)
return true;
tmp = tmp.ImmediateDominator;
}
return false;
}
internal ControlFlowNode(int blockIndex, ExceptionHandler exceptionHandler, ControlFlowNode endFinallyOrFaultNode)
{
this.BlockIndex = blockIndex;
this.NodeType = endFinallyOrFaultNode != null ? ControlFlowNodeType.FinallyOrFaultHandler : ControlFlowNodeType.CatchHandler;
this.ExceptionHandler = exceptionHandler;
this.EndFinallyOrFaultNode = endFinallyOrFaultNode;
Debug.Assert((exceptionHandler.HandlerType == ExceptionHandlerType.Finally || exceptionHandler.HandlerType == ExceptionHandlerType.Fault) == (endFinallyOrFaultNode != null));
this.Offset = exceptionHandler.HandlerStart.Offset;
}
static ControlFlowNode FindCommonDominator(ControlFlowNode b1, ControlFlowNode b2)
{
// Here we could use the postorder numbers to get rid of the hashset, see "A Simple, Fast Dominance Algorithm"
HashSet<ControlFlowNode> path1 = new HashSet<ControlFlowNode>();
while (b1 != null && path1.Add(b1))
b1 = b1.ImmediateDominator;
while (b2 != null) {
if (path1.Contains(b2))
return b2;
else
b2 = b2.ImmediateDominator;
}
throw new Exception("No common dominator found!");
}