/// <summary>
/// Replaces a child of this ILInstruction.
/// </summary>
/// <param name="childPointer">Reference to the field holding the child</param>
/// <param name="newValue">New child</param>
/// <param name="index">Index of the field in the Children collection</param>
protected internal void SetChildInstruction(ref ILInstruction childPointer, ILInstruction newValue, int index)
{
ILInstruction oldValue = childPointer;
Debug.Assert(oldValue == GetChild(index));
if (oldValue == newValue && newValue?.parent == this && newValue.ChildIndex == index)
{
return;
}
childPointer = newValue;
if (newValue != null)
{
newValue.parent = this;
newValue.ChildIndex = index;
}
InvalidateFlags();
MakeDirty();
if (refCount > 0)
{
// The new value may be a subtree of the old value.
// We first call AddRef(), then ReleaseRef() to prevent the subtree
// that stays connected from receiving a Disconnected() notification followed by a Connected() notification.
if (newValue != null)
{
newValue.AddRef();
}
if (oldValue != null)
{
oldValue.ReleaseRef();
}
}
}
/// <summary>
/// Called when a new child is added to a InstructionCollection.
/// </summary>
protected internal void InstructionCollectionAdded(ILInstruction newChild)
{
Debug.Assert(GetChild(newChild.ChildIndex) == newChild);
Debug.Assert(!this.IsDescendantOf(newChild), "ILAst must form a tree");
newChild.parent = this;
if (refCount > 0)
{
newChild.AddRef();
}
}
/// <summary>
/// Called when a new child is added to a InstructionCollection.
/// </summary>
protected internal void InstructionCollectionAdded(ILInstruction newChild)
{
Debug.Assert(GetChild(newChild.ChildIndex) == newChild);
Debug.Assert(!this.IsDescendantOf(newChild), "ILAst must form a tree");
// If a call to ReplaceWith() triggers the "ILAst must form a tree" assertion,
// make sure to read the remarks on the ReplaceWith() method.
newChild.parent = this;
if (refCount > 0)
{
newChild.AddRef();
}
}