/// <inheritdoc />
public void Revert(ControlFlowGraphEditContext <TInstruction> context)
{
if (!_isApplied)
{
throw new InvalidOperationException("Operation is not applied yet.");
}
var node = context.FindNode(BranchOffset);
// Re-merge node if it was split.
if (_hasSplit)
{
var newNeighbour = node.FallThroughNeighbour;
node.FallThroughNeighbour = null;
context.RemoveNodeFromIndex(newNeighbour.Offset);
newNeighbour.MergeWithPredecessor();
}
// Restore original fallthrough neighbour.
node.FallThroughNeighbour = _oldFallThroughOffset.HasValue
? context.FindNode(_oldFallThroughOffset.Value)
: null;
_isApplied = false;
}
/// <inheritdoc />
protected override void OnRevert(ControlFlowGraphEditContext <TInstruction> context)
{
var origin = context.FindNode(OriginOffset);
var target = context.FindNodeOrSplit(TargetOffset, out _);
origin.ConnectWith(target, EdgeType);
}
/// <inheritdoc />
public void Apply(ControlFlowGraphEditContext <TInstruction> context)
{
if (_isApplied)
{
throw new InvalidOperationException("Operation is already applied.");
}
var node = context.FindNode(BranchOffset);
// Save original fallthrough node offset.
_oldFallThroughOffset = node.FallThroughNeighbour?.Offset;
// Set new fallthrough neighbour.
node.FallThroughNeighbour = NewFallThroughOffset.HasValue
? context.FindNodeOrSplit(NewFallThroughOffset.Value, out _hasSplit)
: null;
_isApplied = true;
}
/// <inheritdoc />
protected override void OnRevert(ControlFlowGraphEditContext <TInstruction> context)
{
var origin = context.FindNode(OriginOffset);
var target = context.Graph.Nodes[TargetOffset];
var collection = EdgeType switch
{
ControlFlowEdgeType.Conditional => origin.ConditionalEdges,
ControlFlowEdgeType.Abnormal => origin.AbnormalEdges,
_ => throw new ArgumentOutOfRangeException()
};
collection.Remove(collection.GetEdgesToNeighbour(target).First());
if (_hasSplit)
{
context.RemoveNodeFromIndex(target.Offset);
target.MergeWithPredecessor();
}
}
/// <inheritdoc />
protected override void OnApply(ControlFlowGraphEditContext <TInstruction> context)
{
var origin = context.FindNode(OriginOffset);
var target = context.Graph.Nodes[TargetOffset];
var collection = EdgeType switch
{
ControlFlowEdgeType.Conditional => origin.ConditionalEdges,
ControlFlowEdgeType.Abnormal => origin.AbnormalEdges,
_ => throw new ArgumentOutOfRangeException()
};
collection.Remove(collection.GetEdgesToNeighbour(target).First());
var incomingEdges = target.GetIncomingEdges().ToArray();
if (incomingEdges.Length == 1 && incomingEdges[0].Type == ControlFlowEdgeType.FallThrough)
{
context.RemoveNodeFromIndex(target.Offset);
target.MergeWithPredecessor();
}
}
