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); 792var memberState = GetState(ref state, slot); 793var badState = symbolType.Type.IsPossiblyNullableReferenceTypeTypeParameter() && (annotations & FlowAnalysisAnnotations.NotNull) == 0 794? NullableFlowState.MaybeDefault 795: NullableFlowState.MaybeNull; 851SetState(ref this.State, memberSlot, type.Type.IsPossiblyNullableReferenceTypeTypeParameter() ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull); 1146var parameterState = GetState(ref state, memberSlot); 1178SetState(ref this.State, memberSlot, NullableFlowState.MaybeNull); 1280var parameterState = GetState(ref state, slot); 1336var parameterState = GetState(ref stateWhen, slot); 1363private void EnforceNotNullIfNotNull(SyntaxNode? syntaxOpt, LocalState state, ImmutableArray<ParameterSymbol> parameters, ImmutableHashSet<string> inputParamNames, NullableFlowState outputState, ParameterSymbol? outputParam) 1950private NullableFlowState GetState(ref LocalState state, int slot) 1953return NullableFlowState.NotNull; 1959private void SetState(ref LocalState state, int slot, NullableFlowState value, bool useNotNullsAsDefault = false) 1981private NullableFlowState GetDefaultState(ref LocalState state, int slot) 1986return NullableFlowState.NotNull; 2016return NullableFlowState.NotNull; 2345private static bool ShouldReportNullableAssignment(TypeWithAnnotations type, NullableFlowState state) 2362case NullableFlowState.NotNull: 2364case NullableFlowState.MaybeNull: 2440valueType.State == NullableFlowState.MaybeDefault; 2622var newState = valueType.State; 2725NullableFlowState value = isDefaultValue ? NullableFlowState.MaybeNull : fieldOrPropertyType.ToTypeWithState().State; 2737NullableFlowState.NotNull; 2785/// and the new state is not <see cref="NullableFlowState.NotNull"/>, this method should be called to perform the 2789private void SetStateAndTrackForFinally(ref LocalState state, int slot, NullableFlowState newState) 2793if (newState != NullableFlowState.NotNull && NonMonotonicState.HasValue) 2878private NullableFlowState GetDefaultState(Symbol symbol) 2971var state = GetParameterState(parameterType, parameter.FlowAnalysisAnnotations).State; 3009return TypeWithState.Create(parameterType.Type, NullableFlowState.MaybeDefault); 3014return TypeWithState.Create(parameterType.Type, NullableFlowState.NotNull); 3317SetState(ref state, slot, NullableFlowState.NotNull); 3816SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 3824SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 3929NullableFlowState resultState = getResultState(node, collectionKind); 3935static NullableFlowState getResultState(BoundCollectionExpression node, CollectionExpressionTypeKind collectionKind) 3947return NullableFlowState.NotNull; 4011(int slot, NullableFlowState resultState, Func<TypeSymbol, MethodSymbol?, int>? initialStateInferenceCompletion) = 4031NullableFlowState resultState, 4060NullableFlowState resultState) 4062Debug.Assert(resultState == NullableFlowState.NotNull); 4094(int slot, NullableFlowState resultState, Func<TypeSymbol, MethodSymbol?, int>? completion) inferInitialObjectState( 4102return (-1, NullableFlowState.NotNull, inferInitialObjectStateAsContinuation(node, arguments, argumentResults, hasObjectInitializer)); 4108var resultState = NullableFlowState.NotNull; 4140resultState = NullableFlowState.MaybeNull; 4175Debug.Assert(resultState == NullableFlowState.NotNull); 4309var result = new VisitResult(objectInitializer.Type, NullableAnnotation.NotAnnotated, NullableFlowState.NotNull); 4498SetAnalyzedNullability(node.ImplicitReceiverOpt, new VisitResult(node.ImplicitReceiverOpt.Type, NullableAnnotation.NotAnnotated, NullableFlowState.NotNull)); 4556SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 4561var resultType = TypeWithState.Create(node.Type, NullableFlowState.NotNull); 4669SetResultType(node, TypeWithState.Create(anonymousType, NullableFlowState.NotNull)); 4701SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 4706SetResultType(node, TypeWithState.Create(arrayType, NullableFlowState.NotNull)); 4782var elementState = BestTypeInferrer.GetNullableState(expressionTypes); 4984NullableFlowState resultState = NullableFlowState.NotNull; 5012resultState = NullableFlowState.MaybeNull; // Delegate removal can produce null. 5015resultState = NullableFlowState.NotNull; 5547SetState(ref stateToUpdate, slot, NullableFlowState.NotNull); 5576SetState(ref state, slot, NullableFlowState.NotNull); 5601if (GetState(ref state, slot) == NullableFlowState.NotNull) 5604SetState(ref state, slot, NullableFlowState.MaybeNull); 5633SetState(ref state, childSlot, NullableFlowState.NotNull); 5712SetState(ref this.State, leftSlot, NullableFlowState.NotNull); 5767BoundNullCoalescingOperatorResultKind.NoCommonType => (node.Type, NullableFlowState.NotNull), 5772BoundNullCoalescingOperatorResultKind.RightDynamicType => (rightResultType!, NullableFlowState.NotNull), 5779(TypeSymbol ResultType, NullableFlowState LeftState) getLeftResultType(TypeSymbol leftType, TypeSymbol rightType) 5789return (rightType, NullableFlowState.NotNull); 5794return (leftType, NullableFlowState.NotNull); 5797(TypeSymbol ResultType, NullableFlowState LeftState) getResultStateWithRightType(TypeSymbol leftType, TypeSymbol rightType) 5809TypeWithState.Create(leftType, NullableFlowState.NotNull), 5820return (rightType, NullableFlowState.NotNull); 5992SetResultType(node, TypeWithState.Create(resultType, NullableFlowState.MaybeDefault)); 6047var rValueState = consequenceRValue.State.Join(alternativeRValue.State); 6155NullableFlowState resultState; 6315SetResultType(node, TypeWithState.Create(rvalueType, NullableFlowState.NotNull)); 6646private NullableFlowState LearnFromCompareExchangeMethod(in CompareExchangeInfo compareExchangeInfo) 6666return NullableFlowState.NotNull; 6676var valueFlowState = compareExchangeInfo.Results[valueIndex].RValueType.State; 6683var locationFlowState = compareExchangeInfo.Results[locationIndex].RValueType.State; 6801return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 6806return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7366SetState(ref state, memberSlot, NullableFlowState.NotNull); 7671var adjustedState = LearnFromCompareExchangeMethod(in compareExchangeInfoOpt); 7795return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7801return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 7816return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7820return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 7835return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7839return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 8313NullableFlowState state = GetState(ref this.State, slot); 8588SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 8595SetState(ref this.State, slot, NullableFlowState.NotNull); 8613SetResultType(node, TypeWithState.Create(tupleOpt, NullableFlowState.NotNull)); 8735SetState(ref this.State, targetFieldSlot, NullableFlowState.NotNull); 8752SetState(ref this.State, targetFieldSlot, NullableFlowState.NotNull); 8988NullableFlowState resultState = NullableFlowState.NotNull; 9022resultState = NullableFlowState.NotNull; 9046return TypeWithState.Create(targetType, NullableFlowState.NotNull); 9052resultState = NullableFlowState.NotNull; 9056resultState = NullableFlowState.NotNull; 9061resultState = NullableFlowState.NotNull; 9101resultState = NullableFlowState.NotNull; 9225resultState = NullableFlowState.NotNull; 9295static TypeWithState calculateResultType(TypeWithAnnotations targetTypeWithNullability, bool fromExplicitCast, NullableFlowState resultState, bool isSuppressed, TypeSymbol targetType) 9299resultState = NullableFlowState.NotNull; 9304resultState = targetType?.IsTypeParameterDisallowingAnnotationInCSharp8() == true ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9311static NullableFlowState getReferenceConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType) 9313var state = operandType.State; 9316case NullableFlowState.MaybeNull: 9322return NullableFlowState.MaybeDefault; 9328return (annotation == NullableAnnotation.Annotated) ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9332case NullableFlowState.MaybeDefault: 9335return NullableFlowState.MaybeNull; 9345static NullableFlowState getBoxingConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType) 9347var state = operandType.State; 9348if (state == NullableFlowState.MaybeNull) 9353return NullableFlowState.MaybeDefault; 9363return (annotation == NullableAnnotation.Annotated) ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9373static NullableFlowState getUnboxingConversionResultState(TypeWithState operandType) 9375var state = operandType.State; 9376if (state == NullableFlowState.MaybeNull) 9378return NullableFlowState.MaybeDefault; 9383static NullableFlowState getConversionResultState(TypeWithState operandType) 9385var state = operandType.State; 9386if (state == NullableFlowState.MaybeNull) 9388return NullableFlowState.MaybeDefault; 9516var resultType = TypeWithState.Create(targetType, NullableFlowState.NotNull); 9559NullableFlowState operandState = operandType.State; 9679private TypeWithState GetLiftedReturnType(TypeWithAnnotations returnType, NullableFlowState operandState) 9683NullableFlowState state = returnType.ToTypeWithState().State.Join(operandState); 9700private TypeWithState GetLiftedReturnTypeIfNecessary(bool isLifted, TypeWithAnnotations returnType, NullableFlowState operandState) 9796var result = TypeWithState.Create(delegateType, NullableFlowState.NotNull); 10082var rvalueResult = TypeWithState.Create(node.Type, NullableFlowState.NotNull); 10500var valueBeforeNullableWrapping = TypeWithState.Create(underlyingType.Type, NullableFlowState.NotNull); 10964var state = GetState(ref this.State, slot); 10976SetState(ref this.StateWhenTrue, containingSlot, NullableFlowState.NotNull); 11194if (enumeratorReturnType.State != NullableFlowState.NotNull) 11275var state = NullableFlowState.NotNull; 11471TypeWithState.Create(node.Type, node.OperatorKind.IsLifted() ? argumentResult.State : NullableFlowState.NotNull); 11518return TypeWithState.Create(node.Type, NullableFlowState.NotNull); 11636SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 11658SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.MaybeDefault)); 11673SetState(ref this.State, slot, NullableFlowState.NotNull); 11719NullableFlowState resultState = NullableFlowState.NotNull; 11734resultState = NullableFlowState.MaybeDefault; 11772SetResultType(node, TypeWithState.Create(node.Type, node.Type?.CanContainNull() != false && node.ConstantValueOpt?.IsNull == true ? NullableFlowState.MaybeDefault : NullableFlowState.NotNull)); 11880node.IsAddition ? GetState(ref this.State, memberSlot).Meet(ResultType.State) : NullableFlowState.MaybeNull); 11997private bool ReportPossibleNullReceiverIfNeeded(TypeSymbol type, NullableFlowState state, bool checkNullableValueType, SyntaxNode syntax, out bool reportedDiagnostic) 12056SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12071SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12120SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12126SetResultType(node, TypeWithState.Create(type, NullableFlowState.NotNull)); 12194SetState(ref this.State, slot, NullableFlowState.NotNull); 12283Debug.Assert(ResultType is TypeWithState { Type: FunctionPointerTypeSymbol { }, State: NullableFlowState.NotNull }); 12588SetValue(Id, index, useNotNullsAsDefault ? NullableFlowState.NotNull : walker.GetDefaultState(ref this, slot)); 12592public NullableFlowState this[int slot] 12606private NullableFlowState GetValue(int id, int index) 12616private NullableFlowState GetValue(int index) 12620return NullableFlowState.NotNull; 12627var result = (_state[index], _state[index + 1]) switch 12629(false, false) => NullableFlowState.NotNull, // Should not be reachable 12630(true, false) => NullableFlowState.MaybeNull, 12631(false, true) => NullableFlowState.MaybeDefault, 12632(true, true) => NullableFlowState.NotNull 12638private void SetValue(int id, int index, NullableFlowState value) 12651private void SetValue(int index, NullableFlowState value) 12659NullableFlowState.MaybeNull => (true, false), 12660NullableFlowState.MaybeDefault => (false, true), 12661NullableFlowState.NotNull => (true, true), 12715var oldValue = oldReachable ? GetValue(i) : NullableFlowState.NotNull; 12716var newValue = oldValue.Join(other.GetValue(i)); 12741var oldValue = GetValue(i); 12742var newValue = oldValue.Meet(other.GetValue(i)); 12758var mayBeNull = GetValue(i) is NullableFlowState.MaybeNull or NullableFlowState.MaybeDefault; 12789NullableFlowState.MaybeNull => "?", 12790NullableFlowState.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);

1199static NullableFlowState getTypeArgumentState(in TypeWithAnnotations typeWithAnnotations) 1204return NullableFlowState.NotNull; 1208return type.IsNullableTypeOrTypeParameter() ? NullableFlowState.MaybeNull : NullableFlowState.NotNull; 1213return type.IsTypeParameterDisallowingAnnotationInCSharp8() ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 1215return NullableFlowState.NotNull; 1220return NullableFlowState.NotNull; 1222NullableFlowState? result = null; 1225var constraintState = getTypeArgumentState(constraintType); 1235return result ?? NullableFlowState.MaybeNull; 1238static bool constraintTypeAllows(in TypeWithAnnotations typeWithAnnotations, NullableFlowState state) 1240if (state == NullableFlowState.NotNull) 1267return 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;