private static void ConnectControlFlow(CFGNode from, CFGNode to)
{
Debug.Assert(from != null);
Debug.Assert(to != null);
to.Entries.Add(from);
from.Exits.Add(to);
}
private CFGNode CreateControlFlow(CFGNode entry, ASTNode astNode)
{
CFGNode temp = currentNode;
currentNode = entry;
AppendControlFlow(astNode);
CFGNode exit = currentNode;
currentNode = temp;
return(exit);
}
private List <CFGNode> SplitControlFlow(int num)
{
Debug.Assert(num > 0, $"Invalid split number: {num}");
List <CFGNode> nodes = new List <CFGNode>();
for (int i = 0; i < num; ++i)
{
CFGNode node = factory.MakeNode();
nodes.Add(node);
ConnectControlFlow(currentNode, node);
}
// set to null because we don't know what is the current node at this point
currentNode = null;
return(nodes);
}
private void MergeControlFlow(List <CFGNode> nodes, CFGNode destination = null)
{
Debug.Assert(nodes.Count > 1, $"Invalid merge number: {nodes.Count}");
if (destination == null)
{
destination = factory.MakeNode();
}
foreach (CFGNode node in nodes)
{
if (node != destination)
{
ConnectControlFlow(node, destination);
}
}
currentNode = destination;
}
private static void PrintCFG(CFGNode root)
{
HashSet <CFGNode> visited = new HashSet <CFGNode>();
Queue <CFGNode> queue = new Queue <CFGNode>();
queue.Enqueue(root);
while (queue.Count != 0)
{
CFGNode node = queue.Dequeue();
if (!visited.Contains(node))
{
visited.Add(node);
Console.WriteLine(node);
foreach (CFGNode exit in node.Exits)
{
queue.Enqueue(exit);
}
}
}
}
private CFGBuilder(CFGNodeFactory factory, FunctionCFG currentCFG)
{
this.factory = factory;
this.currentCFG = currentCFG;
this.currentNode = currentCFG.Entry;
}
public FunctionCFG()
{
Entry = null;
Exit = null;
}