public ILInstruction GetCommonParent(ILInstruction other)
{
if (other == null)
{
throw new ArgumentNullException(nameof(other));
}
ILInstruction a = this;
ILInstruction b = other;
int levelA = a.CountAncestors();
int levelB = b.CountAncestors();
while (levelA > levelB)
{
a = a.Parent;
levelA--;
}
while (levelB > levelA)
{
b = b.Parent;
levelB--;
}
while (a != b)
{
a = a.Parent;
b = b.Parent;
}
return(a);
}
public bool IsBefore(ILInstruction other)
{
if (other == null)
{
throw new ArgumentNullException(nameof(other));
}
ILInstruction a = this;
ILInstruction b = other;
int levelA = a.CountAncestors();
int levelB = b.CountAncestors();
int originalLevelA = levelA;
int originalLevelB = levelB;
while (levelA > levelB)
{
a = a.Parent !;
levelA--;
}
while (levelB > levelA)
{
b = b.Parent !;
levelB--;
}
if (a == b)
{
// a or b is a descendant of the other,
// whichever node has the higher level comes first in post-order walk.
return(originalLevelA > originalLevelB);
}
while (a.Parent != b.Parent)
{
a = a.Parent !;
b = b.Parent !;
}
// now a and b have the same parent or are both root nodes
return(a.ChildIndex < b.ChildIndex);
}