static CSharpControlFlowNullReferenceState GetExpressionNullReferenceState(
[NotNull] NullnessProvider nullnessProvider,
[NotNull] CSharpControlFlowGraphInspector inspector,
[NotNull] HashSet <IAsExpression> alwaysSuccessTryCastExpressions,
ICSharpExpression expression)
{
switch (expression)
{
case IReferenceExpression referenceExpression:
var nullReferenceState = inspector.GetExpressionNullReferenceState(referenceExpression, true);
if (nullReferenceState == CSharpControlFlowNullReferenceState.UNKNOWN)
{
return(GetExpressionNullReferenceStateByAnnotations(nullnessProvider, referenceExpression));
}
return(nullReferenceState);
case IAsExpression asExpression when alwaysSuccessTryCastExpressions.Contains(asExpression):
return(CSharpControlFlowNullReferenceState.NOT_NULL);
case IObjectCreationExpression _: return(CSharpControlFlowNullReferenceState.NOT_NULL);
case IInvocationExpression invocationExpression:
if (invocationExpression.InvokedExpression is IReferenceExpression invokedExpression)
{
return(GetExpressionNullReferenceStateByAnnotations(nullnessProvider, invokedExpression));
}
goto default;
default: return(CSharpControlFlowNullReferenceState.UNKNOWN);
}
}
CSharpControlFlowNullReferenceState GetExpressionNullReferenceState(
[CanBeNull] CSharpCompilerNullableInspector nullabilityInspector,
[CanBeNull] CSharpControlFlowGraphInspector inspector,
[CanBeNull][ItemNotNull] HashSet <IAsExpression> alwaysSuccessTryCastExpressions,
[NotNull] ICSharpExpression expression)
{
if (nullabilityInspector != null)
{
return(GetExpressionNullReferenceStateByNullableContext(nullabilityInspector, expression));
}
Debug.Assert(inspector != null);
Debug.Assert(alwaysSuccessTryCastExpressions != null);
while (true)
{
switch (expression)
{
case IReferenceExpression referenceExpression:
if (referenceExpression is IConditionalAccessExpression conditionalAccessExpression &&
conditionalAccessExpression.HasConditionalAccessSign)
{
var referenceState = GetExpressionNullReferenceStateByAnnotations(referenceExpression);
if (referenceState == CSharpControlFlowNullReferenceState.NOT_NULL)
{
expression = conditionalAccessExpression.ConditionalQualifier;
continue;
}
}
var nullReferenceState = inspector.GetExpressionNullReferenceState(referenceExpression, true);
if (nullReferenceState == CSharpControlFlowNullReferenceState.UNKNOWN)
{
nullReferenceState = GetExpressionNullReferenceStateByAnnotations(referenceExpression);
}
return(nullReferenceState);
case IAsExpression asExpression when alwaysSuccessTryCastExpressions.Contains(asExpression):
return(CSharpControlFlowNullReferenceState.NOT_NULL);
case IObjectCreationExpression _: return(CSharpControlFlowNullReferenceState.NOT_NULL);
case IInvocationExpression invocationExpression:
if (invocationExpression.InvokedExpression is IReferenceExpression invokedExpression)
{
return(GetExpressionNullReferenceStateByAnnotations(invokedExpression));
}
goto default;
default: return(CSharpControlFlowNullReferenceState.UNKNOWN);
}
}
}