/// <summary>
/// Applies all edits to the control flow graph.
/// </summary>
/// <param name="graph">The graph to apply the transaction on.</param>
/// <exception cref="InvalidOperationException">Occurs when the transaction was already applied.</exception>
/// <remarks>
/// When an exception occurs within one of the edits, all edits previously applied will be reverted.
/// </remarks>
public void Apply(ControlFlowGraph <TInstruction> graph)
{
if (IsCompleted)
{
throw new InvalidOperationException("The transaction is already applied.");
}
var context = new ControlFlowGraphEditContext <TInstruction>(graph);
int index = 0;
try
{
for (; index < _actions.Count; index++)
{
var edit = _actions[index];
edit.Apply(context);
}
IsCompleted = true;
}
catch
{
index--;
for (; index >= 0; index--)
{
_actions[index].Revert(context);
}
throw;
}
}
/// <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 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 />
public void Apply(ControlFlowGraphEditContext <TInstruction> context)
{
if (_isApplied)
{
throw new InvalidOperationException("Operation is already applied.");
}
context.FindNodeOrSplit(SplitOffset, out _hasSplit);
_isApplied = true;
}
/// <inheritdoc />
public void Revert(ControlFlowGraphEditContext <TInstruction> context)
{
if (!_isApplied)
{
throw new InvalidOperationException("Operation is not applied yet.");
}
OnRevert(context);
_isApplied = false;
}
/// <inheritdoc />
public void Apply(ControlFlowGraphEditContext <TInstruction> context)
{
if (_isApplied)
{
throw new InvalidOperationException("Operation is already applied.");
}
OnApply(context);
_isApplied = true;
}
/// <inheritdoc />
public void Revert(ControlFlowGraphEditContext <TInstruction> context)
{
if (!_isApplied)
{
throw new InvalidOperationException("Operation is not applied yet.");
}
if (_hasSplit)
{
var node = context.Graph.Nodes[SplitOffset];
context.RemoveNodeFromIndex(SplitOffset);
node.MergeWithPredecessor();
}
}
/// <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();
}
}
/// <summary> /// Reverts the update to the adjacency list of the node. /// </summary> /// <param name="context">The editing context.</param> /// <remarks> /// This method is guaranteed to be called after <see cref="Apply"/>. /// </remarks> protected abstract void OnRevert(ControlFlowGraphEditContext <TInstruction> context);