public CorePointsToAnalysisData MergeCoreAnalysisDataForBackEdge(
PointsToAnalysisData forwardEdgeAnalysisData,
PointsToAnalysisData backEdgeAnalysisData,
Func <PointsToAbstractValue, ImmutableHashSet <AnalysisEntity> > getChildAnalysisEntities,
Action <AnalysisEntity, PointsToAnalysisData> resetAbstractValue)
{
// Stop tracking points to values present in both branches if their is an assignment to a may-be null value from the back edge.
// Clone the input forwardEdgeAnalysisData to ensure we don't overwrite the input dictionary.
forwardEdgeAnalysisData = (PointsToAnalysisData)forwardEdgeAnalysisData.Clone();
List <AnalysisEntity> keysInMap1 = forwardEdgeAnalysisData.CoreAnalysisData.Keys.ToList();
foreach (var key in keysInMap1)
{
var forwardEdgeValue = forwardEdgeAnalysisData[key];
if (backEdgeAnalysisData.TryGetValue(key, out var backEdgeValue) &&
backEdgeValue != forwardEdgeValue)
{
switch (backEdgeValue.NullState)
{
case NullAbstractValue.MaybeNull:
stopTrackingAnalysisDataForKeyAndChildren();
break;
case NullAbstractValue.NotNull:
if (backEdgeValue.MakeMayBeNull() != forwardEdgeValue)
{
if (forwardEdgeValue.NullState == NullAbstractValue.NotNull)
{
stopTrackingAnalysisDataForChildren();
}
else
{
stopTrackingAnalysisDataForKeyAndChildren();
}
}
break;
}
void stopTrackingAnalysisDataForKeyAndChildren()
{
stopTrackingAnalysisDataForChildren();
stopTrackingAnalysisDataForEntity(key);
}
void stopTrackingAnalysisDataForChildren()
{
var childEntities = getChildAnalysisEntities(forwardEdgeValue)
.AddRange(getChildAnalysisEntities(backEdgeValue));
foreach (var childEntity in childEntities)
{
stopTrackingAnalysisDataForEntity(childEntity);
}
}
void stopTrackingAnalysisDataForEntity(AnalysisEntity entity)
{
if (entity.IsChildOrInstanceMember)
{
resetAbstractValue(entity, forwardEdgeAnalysisData);
}
}
}
}
var resultMap = Merge(forwardEdgeAnalysisData.CoreAnalysisData, backEdgeAnalysisData.CoreAnalysisData);
Debug.Assert(Compare(forwardEdgeAnalysisData.CoreAnalysisData, resultMap) <= 0);
Debug.Assert(Compare(backEdgeAnalysisData.CoreAnalysisData, resultMap) <= 0);
return(resultMap);
}
