36public static NullableFlowState GetNullableState(ArrayBuilder<TypeWithState> types) 38NullableFlowState result = NullableFlowState.NotNull;

126public VisitResult(TypeSymbol? type, NullableAnnotation annotation, NullableFlowState state) 216private static readonly TypeWithState _invalidType = TypeWithState.Create(new UnsupportedMetadataTypeSymbol(), NullableFlowState.NotNull); 796var memberState = GetState(ref state, slot); 797var badState = symbolType.Type.IsPossiblyNullableReferenceTypeTypeParameter() && (annotations & FlowAnalysisAnnotations.NotNull) == 0 798? NullableFlowState.MaybeDefault 799: NullableFlowState.MaybeNull; 855SetState(ref this.State, memberSlot, type.Type.IsPossiblyNullableReferenceTypeTypeParameter() ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull); 1150var parameterState = GetState(ref state, memberSlot); 1182SetState(ref this.State, memberSlot, NullableFlowState.MaybeNull); 1295var parameterState = GetState(ref state, slot); 1351var parameterState = GetState(ref stateWhen, slot); 1378private void EnforceNotNullIfNotNull(SyntaxNode? syntaxOpt, LocalState state, ImmutableArray<ParameterSymbol> parameters, ImmutableHashSet<string> inputParamNames, NullableFlowState outputState, ParameterSymbol? outputParam) 1965private NullableFlowState GetState(ref LocalState state, int slot) 1968return NullableFlowState.NotNull; 1974private void SetState(ref LocalState state, int slot, NullableFlowState value, bool useNotNullsAsDefault = false) 1996private NullableFlowState GetDefaultState(ref LocalState state, int slot) 2001return NullableFlowState.NotNull; 2031return NullableFlowState.NotNull; 2360private static bool ShouldReportNullableAssignment(TypeWithAnnotations type, NullableFlowState state) 2377case NullableFlowState.NotNull: 2379case NullableFlowState.MaybeNull: 2455valueType.State == NullableFlowState.MaybeDefault; 2637var newState = valueType.State; 2740NullableFlowState value = isDefaultValue ? NullableFlowState.MaybeNull : fieldOrPropertyType.ToTypeWithState().State; 2752NullableFlowState.NotNull; 2800/// and the new state is not <see cref="NullableFlowState.NotNull"/>, this method should be called to perform the 2804private void SetStateAndTrackForFinally(ref LocalState state, int slot, NullableFlowState newState) 2808if (newState != NullableFlowState.NotNull && NonMonotonicState.HasValue) 2893private NullableFlowState GetDefaultState(Symbol symbol) 2986var state = GetParameterState(parameterType, parameter.FlowAnalysisAnnotations).State; 3024return TypeWithState.Create(parameterType.Type, NullableFlowState.MaybeDefault); 3029return TypeWithState.Create(parameterType.Type, NullableFlowState.NotNull); 3333SetState(ref state, slot, NullableFlowState.NotNull); 3832SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 3840SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 3945NullableFlowState resultState = getResultState(node, collectionKind); 3951static NullableFlowState getResultState(BoundCollectionExpression node, CollectionExpressionTypeKind collectionKind) 3963return NullableFlowState.NotNull; 4027(int slot, NullableFlowState resultState, Func<TypeSymbol, MethodSymbol?, int>? initialStateInferenceCompletion) = 4047NullableFlowState resultState, 4076NullableFlowState resultState) 4078Debug.Assert(resultState == NullableFlowState.NotNull); 4110(int slot, NullableFlowState resultState, Func<TypeSymbol, MethodSymbol?, int>? completion) inferInitialObjectState( 4118return (-1, NullableFlowState.NotNull, inferInitialObjectStateAsContinuation(node, arguments, argumentResults, hasObjectInitializer)); 4124var resultState = NullableFlowState.NotNull; 4156resultState = NullableFlowState.MaybeNull; 4191Debug.Assert(resultState == NullableFlowState.NotNull); 4325var result = new VisitResult(objectInitializer.Type, NullableAnnotation.NotAnnotated, NullableFlowState.NotNull); 4514SetAnalyzedNullability(node.ImplicitReceiverOpt, new VisitResult(node.ImplicitReceiverOpt.Type, NullableAnnotation.NotAnnotated, NullableFlowState.NotNull)); 4572SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 4577var resultType = TypeWithState.Create(node.Type, NullableFlowState.NotNull); 4685SetResultType(node, TypeWithState.Create(anonymousType, NullableFlowState.NotNull)); 4717SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 4722SetResultType(node, TypeWithState.Create(arrayType, NullableFlowState.NotNull)); 4798var elementState = BestTypeInferrer.GetNullableState(expressionTypes); 5000NullableFlowState resultState = NullableFlowState.NotNull; 5028resultState = NullableFlowState.MaybeNull; // Delegate removal can produce null. 5031resultState = NullableFlowState.NotNull; 5558SetState(ref stateToUpdate, slot, NullableFlowState.NotNull); 5587SetState(ref state, slot, NullableFlowState.NotNull); 5612if (GetState(ref state, slot) == NullableFlowState.NotNull) 5615SetState(ref state, slot, NullableFlowState.MaybeNull); 5644SetState(ref state, childSlot, NullableFlowState.NotNull); 5723SetState(ref this.State, leftSlot, NullableFlowState.NotNull); 5778BoundNullCoalescingOperatorResultKind.NoCommonType => (node.Type, NullableFlowState.NotNull), 5783BoundNullCoalescingOperatorResultKind.RightDynamicType => (rightResultType!, NullableFlowState.NotNull), 5790(TypeSymbol ResultType, NullableFlowState LeftState) getLeftResultType(TypeSymbol leftType, TypeSymbol rightType) 5800return (rightType, NullableFlowState.NotNull); 5805return (leftType, NullableFlowState.NotNull); 5808(TypeSymbol ResultType, NullableFlowState LeftState) getResultStateWithRightType(TypeSymbol leftType, TypeSymbol rightType) 5820TypeWithState.Create(leftType, NullableFlowState.NotNull), 5831return (rightType, NullableFlowState.NotNull); 6004SetResultType(node, TypeWithState.Create(resultType, NullableFlowState.MaybeDefault)); 6059var rValueState = consequenceRValue.State.Join(alternativeRValue.State); 6167NullableFlowState resultState; 6327SetResultType(node, TypeWithState.Create(rvalueType, NullableFlowState.NotNull)); 6763private NullableFlowState LearnFromCompareExchangeMethod(in CompareExchangeInfo compareExchangeInfo) 6783return NullableFlowState.NotNull; 6793var valueFlowState = compareExchangeInfo.Results[valueIndex].RValueType.State; 6800var locationFlowState = compareExchangeInfo.Results[locationIndex].RValueType.State; 6917return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 6922return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7512SetState(ref state, memberSlot, NullableFlowState.NotNull); 7817var adjustedState = LearnFromCompareExchangeMethod(in compareExchangeInfoOpt); 7941return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7947return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 7962return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7966return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 7981return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7985return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 8497NullableFlowState state = GetState(ref this.State, slot); 8771SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 8778SetState(ref this.State, slot, NullableFlowState.NotNull); 8796SetResultType(node, TypeWithState.Create(tupleOpt, NullableFlowState.NotNull)); 8918SetState(ref this.State, targetFieldSlot, NullableFlowState.NotNull); 8935SetState(ref this.State, targetFieldSlot, NullableFlowState.NotNull); 9171NullableFlowState resultState = NullableFlowState.NotNull; 9203resultState = NullableFlowState.NotNull; 9227return TypeWithState.Create(targetType, NullableFlowState.NotNull); 9233resultState = NullableFlowState.NotNull; 9237resultState = NullableFlowState.NotNull; 9242resultState = NullableFlowState.NotNull; 9282resultState = NullableFlowState.NotNull; 9406resultState = NullableFlowState.NotNull; 9476static TypeWithState calculateResultType(TypeWithAnnotations targetTypeWithNullability, bool fromExplicitCast, NullableFlowState resultState, bool isSuppressed, TypeSymbol targetType) 9480resultState = NullableFlowState.NotNull; 9485resultState = targetType?.IsTypeParameterDisallowingAnnotationInCSharp8() == true ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9492static NullableFlowState getReferenceConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType) 9494var state = operandType.State; 9497case NullableFlowState.MaybeNull: 9503return NullableFlowState.MaybeDefault; 9509return (annotation == NullableAnnotation.Annotated) ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9513case NullableFlowState.MaybeDefault: 9516return NullableFlowState.MaybeNull; 9526static NullableFlowState getBoxingConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType) 9528var state = operandType.State; 9529if (state == NullableFlowState.MaybeNull) 9534return NullableFlowState.MaybeDefault; 9544return (annotation == NullableAnnotation.Annotated) ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9554static NullableFlowState getUnboxingConversionResultState(TypeWithState operandType) 9556var state = operandType.State; 9557if (state == NullableFlowState.MaybeNull) 9559return NullableFlowState.MaybeDefault; 9564static NullableFlowState getConversionResultState(TypeWithState operandType) 9566var state = operandType.State; 9567if (state == NullableFlowState.MaybeNull) 9569return NullableFlowState.MaybeDefault; 9697var resultType = TypeWithState.Create(targetType, NullableFlowState.NotNull); 9740NullableFlowState operandState = operandType.State; 9860private TypeWithState GetLiftedReturnType(TypeWithAnnotations returnType, NullableFlowState operandState) 9864NullableFlowState state = returnType.ToTypeWithState().State.Join(operandState); 9881private TypeWithState GetLiftedReturnTypeIfNecessary(bool isLifted, TypeWithAnnotations returnType, NullableFlowState operandState) 9977var result = TypeWithState.Create(delegateType, NullableFlowState.NotNull); 10274var rvalueResult = TypeWithState.Create(node.Type, NullableFlowState.NotNull); 10694var valueBeforeNullableWrapping = TypeWithState.Create(underlyingType.Type, NullableFlowState.NotNull); 11221var state = GetState(ref this.State, slot); 11233SetState(ref this.StateWhenTrue, containingSlot, NullableFlowState.NotNull); 11451if (enumeratorReturnType.State != NullableFlowState.NotNull) 11532var state = NullableFlowState.NotNull; 11728TypeWithState.Create(node.Type, node.OperatorKind.IsLifted() ? argumentResult.State : NullableFlowState.NotNull); 11775return TypeWithState.Create(node.Type, NullableFlowState.NotNull); 11893SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 11915SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.MaybeDefault)); 11930SetState(ref this.State, slot, NullableFlowState.NotNull); 11976NullableFlowState resultState = NullableFlowState.NotNull; 11991resultState = NullableFlowState.MaybeDefault; 12029SetResultType(node, TypeWithState.Create(node.Type, node.Type?.CanContainNull() != false && node.ConstantValueOpt?.IsNull == true ? NullableFlowState.MaybeDefault : NullableFlowState.NotNull)); 12137node.IsAddition ? GetState(ref this.State, memberSlot).Meet(ResultType.State) : NullableFlowState.MaybeNull); 12254private bool ReportPossibleNullReceiverIfNeeded(TypeSymbol type, NullableFlowState state, bool checkNullableValueType, SyntaxNode syntax, out bool reportedDiagnostic) 12313SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12328SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12377SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12383SetResultType(node, TypeWithState.Create(type, NullableFlowState.NotNull)); 12451SetState(ref this.State, slot, NullableFlowState.NotNull); 12540Debug.Assert(ResultType is TypeWithState { Type: FunctionPointerTypeSymbol { }, State: NullableFlowState.NotNull }); 12845SetValue(Id, index, useNotNullsAsDefault ? NullableFlowState.NotNull : walker.GetDefaultState(ref this, slot)); 12849public NullableFlowState this[int slot] 12863private NullableFlowState GetValue(int id, int index) 12873private NullableFlowState GetValue(int index) 12877return NullableFlowState.NotNull; 12884var result = (_state[index], _state[index + 1]) switch 12886(false, false) => NullableFlowState.NotNull, // Should not be reachable 12887(true, false) => NullableFlowState.MaybeNull, 12888(false, true) => NullableFlowState.MaybeDefault, 12889(true, true) => NullableFlowState.NotNull 12895private void SetValue(int id, int index, NullableFlowState value) 12908private void SetValue(int index, NullableFlowState value) 12916NullableFlowState.MaybeNull => (true, false), 12917NullableFlowState.MaybeDefault => (false, true), 12918NullableFlowState.NotNull => (true, true), 12972var oldValue = oldReachable ? GetValue(i) : NullableFlowState.NotNull; 12973var newValue = oldValue.Join(other.GetValue(i)); 12998var oldValue = GetValue(i); 12999var newValue = oldValue.Meet(other.GetValue(i)); 13015var mayBeNull = GetValue(i) is NullableFlowState.MaybeNull or NullableFlowState.MaybeDefault; 13046NullableFlowState.MaybeNull => "?", 13047NullableFlowState.MaybeDefault => "??",

481SetState(ref State, outputSlot, NullableFlowState.NotNull); 577SetState(ref this.State, outputSlot, NullableFlowState.NotNull); // Slice value is assumed to be never null 680var tempState = GetState(ref this.State, tempSlot); 956NullableFlowState inferredState; 1006NullableFlowState inferredState = BestTypeInferrer.GetNullableState(resultTypes);

1228static NullableFlowState getTypeArgumentState(in TypeWithAnnotations typeWithAnnotations) 1233return NullableFlowState.NotNull; 1237return type.IsNullableTypeOrTypeParameter() ? NullableFlowState.MaybeNull : NullableFlowState.NotNull; 1242return type.IsTypeParameterDisallowingAnnotationInCSharp8() ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 1244return NullableFlowState.NotNull; 1249return NullableFlowState.NotNull; 1251NullableFlowState? result = null; 1254var constraintState = getTypeArgumentState(constraintType); 1264return result ?? NullableFlowState.MaybeNull; 1267static bool constraintTypeAllows(in TypeWithAnnotations typeWithAnnotations, NullableFlowState state) 1269if (state == NullableFlowState.NotNull) 1296return state == NullableFlowState.MaybeNull;

104var flowState = TypeWithAnnotations.Create(type, annotation).ToTypeWithState().State;

11/// When in doubt we conservatively use <see cref="NullableFlowState.NotNull"/>

13public static bool MayBeNull(this NullableFlowState state) => state != NullableFlowState.NotNull; 15public static bool IsNotNull(this NullableFlowState state) => state == NullableFlowState.NotNull; 19/// The result is <see cref="NullableFlowState.MaybeNull"/> if either operand is that. 21public static NullableFlowState Join(this NullableFlowState a, NullableFlowState b) => (a > b) ? a : b; 25/// The result is <see cref="NullableFlowState.NotNull"/> if either operand is that. 27public static NullableFlowState Meet(this NullableFlowState a, NullableFlowState b) => (a < b) ? a : b; 29internal static CodeAnalysis.NullableFlowState ToPublicFlowState(this CSharp.NullableFlowState nullableFlowState) => 32CSharp.NullableFlowState.NotNull => CodeAnalysis.NullableFlowState.NotNull, 33CSharp.NullableFlowState.MaybeNull => CodeAnalysis.NullableFlowState.MaybeNull, 34CSharp.NullableFlowState.MaybeDefault => CodeAnalysis.NullableFlowState.MaybeNull, 39public static CSharp.NullableFlowState ToInternalFlowState(this CodeAnalysis.NullableFlowState flowState) => 42CodeAnalysis.NullableFlowState.None => CSharp.NullableFlowState.NotNull, 43CodeAnalysis.NullableFlowState.NotNull => CSharp.NullableFlowState.NotNull, 44CodeAnalysis.NullableFlowState.MaybeNull => CSharp.NullableFlowState.MaybeNull,

813static NullableFlowState getFlowState(TypeSymbol type, NullableAnnotation annotation) 817return annotation.IsAnnotated() ? NullableFlowState.MaybeDefault : NullableFlowState.NotNull; 821return annotation switch { NullableAnnotation.Annotated => NullableFlowState.MaybeDefault, NullableAnnotation.NotAnnotated => NullableFlowState.MaybeNull, _ => NullableFlowState.NotNull }; 825return annotation switch { NullableAnnotation.Annotated => NullableFlowState.MaybeDefault, _ => NullableFlowState.NotNull }; 829return NullableFlowState.MaybeNull; 831return annotation switch { NullableAnnotation.Annotated => NullableFlowState.MaybeNull, _ => NullableFlowState.NotNull };

17public readonly NullableFlowState State; 20public bool MayBeNull => State == NullableFlowState.MaybeNull; 21public bool IsNotNull => State == NullableFlowState.NotNull; 25return Create(type, NullableFlowState.MaybeDefault); 28public static TypeWithState Create(TypeSymbol? type, NullableFlowState defaultState) 30if (defaultState == NullableFlowState.MaybeDefault && 36var state = defaultState != NullableFlowState.NotNull && type?.CanContainNull() != false ? NullableFlowState.MaybeNull : NullableFlowState.NotNull; 45NullableFlowState state; 50state = NullableFlowState.MaybeDefault; 54state = NullableFlowState.NotNull; 63state = NullableFlowState.NotNull; 69private TypeWithState(TypeSymbol? type, NullableFlowState state) 71Debug.Assert(state == NullableFlowState.NotNull || type?.CanContainNull() != false); 72Debug.Assert(state != NullableFlowState.MaybeDefault || type is null || type.IsTypeParameterDisallowingAnnotationInCSharp8()); 81public TypeWithState WithNotNullState() => new TypeWithState(Type, NullableFlowState.NotNull); 83public TypeWithState WithSuppression(bool suppress) => suppress ? new TypeWithState(Type, NullableFlowState.NotNull) : this; 90return (State == NullableFlowState.MaybeDefault || asAnnotatedType) ? type.SetIsAnnotated(compilation) : type;