private void CollectBlocks(ControlFlowGraph graph, ICollection <ILInstruction> instructions, ICollection <long> blockHeaders)
{
Node currentNode = null;
ILBasicBlock currentBlock = null;
foreach (var instruction in instructions.OrderBy(x => x.Offset))
{
// If current instruction is a basic block header, we start a new block.
if (currentNode == null || blockHeaders.Contains(instruction.Offset))
{
currentNode = graph.Nodes.Add(graph.GetNodeName(instruction.Offset));
currentBlock = new ILBasicBlock();
currentNode.UserData[ILBasicBlock.BasicBlockProperty] = currentBlock;
}
// Add instruction to current block.
currentBlock.Instructions.Add(instruction);
// If next offset is also a header, we also create a new block.
// This check is necessary as blocks might not appear in sequence after each other.
if (blockHeaders.Contains(instruction.Offset + instruction.Size))
{
currentNode = null;
}
}
}
private Node GetNode(ControlFlowGraph graph, long offset)
{
string name = graph.GetNodeName(offset);
if (!graph.Nodes.TryGetNode(name, out var node))
{
Logger.Error(Tag, $"Reference to an unexplored basic block IL_{offset:X4} found. Inserting dummy node.");
node = graph.Nodes.Add(name);
}
return(node);
}
