private void AnalyzeOperationBlock(
OperationBlockAnalysisContext operationBlockContext,
DisposeAnalysisHelper disposeAnalysisHelper,
ConcurrentDictionary <Location, bool> reportedLocations)
{
// We are only intersted in analyzing method bodies that have at least one disposable object creation.
if (!(operationBlockContext.OwningSymbol is IMethodSymbol containingMethod) ||
!disposeAnalysisHelper.HasAnyDisposableCreationDescendant(operationBlockContext.OperationBlocks, containingMethod))
{
return;
}
PerformFlowAnalysisOnOperationBlock(operationBlockContext, disposeAnalysisHelper, reportedLocations, containingMethod);
}
private void OnMethodOperationBlockStart(OperationBlockStartAnalysisContext operationBlockStartContext, IMethodSymbol containingMethod)
{
// Shared PointsTo dataflow analysis result for all the callbacks to AnalyzeFieldReference
// for this method's executable code.
PointsToAnalysisResult lazyPointsToAnalysisResult = null;
// If we have any potential disposable object creation descendant within the operation blocks,
// register an operation action to analyze field references where field might be assigned a disposable object.
if (_disposeAnalysisHelper.HasAnyDisposableCreationDescendant(operationBlockStartContext.OperationBlocks, containingMethod))
{
operationBlockStartContext.RegisterOperationAction(AnalyzeFieldReference, OperationKind.FieldReference);
}
// If this is a Dispose method, then analyze dispose invocations for fields within this method.
if (_disposeAnalysisHelper.IsAnyDisposeMethod(containingMethod))
{
AnalyzeDisposeMethod();
}
return;
// Local function
void AnalyzeFieldReference(OperationAnalysisContext operationContext)
{
var fieldReference = (IFieldReferenceOperation)operationContext.Operation;
var field = fieldReference.Field;
// Check if this is a Disposable field that is not currently being tracked.
if (_fieldDisposeValueMap.ContainsKey(field) ||
!_disposableFields.Contains(field) ||
_hasErrors)
{
return;
}
// Only track instance fields on the current instance.
if (field.IsStatic || fieldReference.Instance?.Kind != OperationKind.InstanceReference)
{
return;
}
// We have a field reference for a disposable field.
// Check if it is being assigned a locally created disposable object.
if (fieldReference.Parent is ISimpleAssignmentOperation simpleAssignmentOperation &&
simpleAssignmentOperation.Target == fieldReference)
{
if (lazyPointsToAnalysisResult == null)
{
if (_disposeAnalysisHelper.TryGetOrComputeResult(
operationBlockStartContext, containingMethod,
s_disposableFieldsShouldBeDisposedRule,
trackInstanceFields: false,
out _, out var pointsToAnalysisResult) &&
pointsToAnalysisResult != null)
{
Interlocked.CompareExchange(ref lazyPointsToAnalysisResult, pointsToAnalysisResult, null);
}
else
{
_hasErrors = true;
return;
}
}
PointsToAbstractValue assignedPointsToValue = lazyPointsToAnalysisResult[simpleAssignmentOperation.Value.Kind, simpleAssignmentOperation.Value.Syntax];
foreach (var location in assignedPointsToValue.Locations)
{
if (_disposeAnalysisHelper.IsDisposableCreationOrDisposeOwnershipTransfer(location, containingMethod))
{
AddOrUpdateFieldDisposedValue(field, disposed: false);
break;
}
}
}
}
void AnalyzeDisposeMethod()
{
if (_hasErrors)
{
return;
}
// Perform dataflow analysis to compute dispose value of disposable fields at the end of dispose method.
if (_disposeAnalysisHelper.TryGetOrComputeResult(operationBlockStartContext, containingMethod,
s_disposableFieldsShouldBeDisposedRule, trackInstanceFields: true,
disposeAnalysisResult: out var disposeAnalysisResult,
pointsToAnalysisResult: out var pointsToAnalysisResult))
{
BasicBlock exitBlock = disposeAnalysisResult.ControlFlowGraph.GetExit();
foreach (var fieldWithPointsToValue in disposeAnalysisResult.TrackedInstanceFieldPointsToMap)
{
IFieldSymbol field = fieldWithPointsToValue.Key;
PointsToAbstractValue pointsToValue = fieldWithPointsToValue.Value;
if (!_disposableFields.Contains(field))
{
continue;
}
ImmutableDictionary <AbstractLocation, DisposeAbstractValue> disposeDataAtExit = disposeAnalysisResult.ExitBlockOutput.Data;
var disposed = false;
foreach (var location in pointsToValue.Locations)
{
if (disposeDataAtExit.TryGetValue(location, out DisposeAbstractValue disposeValue))
{
switch (disposeValue.Kind)
{
// For MaybeDisposed, conservatively mark the field as disposed as we don't support path sensitive analysis.
case DisposeAbstractValueKind.MaybeDisposed:
case DisposeAbstractValueKind.Unknown:
case DisposeAbstractValueKind.Escaped:
case DisposeAbstractValueKind.Disposed:
disposed = true;
AddOrUpdateFieldDisposedValue(field, disposed);
break;
}
}
if (disposed)
{
break;
}
}
}
}
