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

126public VisitResult(TypeSymbol? type, NullableAnnotation annotation, NullableFlowState state) 210private static readonly TypeWithState _invalidType = TypeWithState.Create(new UnsupportedMetadataTypeSymbol(), NullableFlowState.NotNull); 783var memberState = GetState(ref state, slot); 784var badState = symbolType.Type.IsPossiblyNullableReferenceTypeTypeParameter() && (annotations & FlowAnalysisAnnotations.NotNull) == 0 785? NullableFlowState.MaybeDefault 786: NullableFlowState.MaybeNull; 842SetState(ref this.State, memberSlot, type.Type.IsPossiblyNullableReferenceTypeTypeParameter() ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull); 1137var parameterState = GetState(ref state, memberSlot); 1169SetState(ref this.State, memberSlot, NullableFlowState.MaybeNull); 1271var parameterState = GetState(ref state, slot); 1327var parameterState = GetState(ref stateWhen, slot); 1354private void EnforceNotNullIfNotNull(SyntaxNode? syntaxOpt, LocalState state, ImmutableArray<ParameterSymbol> parameters, ImmutableHashSet<string> inputParamNames, NullableFlowState outputState, ParameterSymbol? outputParam) 1930private NullableFlowState GetState(ref LocalState state, int slot) 1933return NullableFlowState.NotNull; 1939private void SetState(ref LocalState state, int slot, NullableFlowState value, bool useNotNullsAsDefault = false) 1961private NullableFlowState GetDefaultState(ref LocalState state, int slot) 1966return NullableFlowState.NotNull; 1996return NullableFlowState.NotNull; 2325private static bool ShouldReportNullableAssignment(TypeWithAnnotations type, NullableFlowState state) 2342case NullableFlowState.NotNull: 2344case NullableFlowState.MaybeNull: 2420valueType.State == NullableFlowState.MaybeDefault; 2602var newState = valueType.State; 2702NullableFlowState value = isDefaultValue ? NullableFlowState.MaybeNull : fieldOrPropertyType.ToTypeWithState().State; 2714NullableFlowState.NotNull; 2746/// and the new state is not <see cref="NullableFlowState.NotNull"/>, this method should be called to perform the 2750private void SetStateAndTrackForFinally(ref LocalState state, int slot, NullableFlowState newState) 2754if (newState != NullableFlowState.NotNull && NonMonotonicState.HasValue) 2801private NullableFlowState GetDefaultState(Symbol symbol) 2892var state = GetParameterState(parameterType, parameter.FlowAnalysisAnnotations).State; 2930return TypeWithState.Create(parameterType.Type, NullableFlowState.MaybeDefault); 2935return TypeWithState.Create(parameterType.Type, NullableFlowState.NotNull); 3238SetState(ref state, slot, NullableFlowState.NotNull); 3737SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 3745SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 3850NullableFlowState resultState = getResultState(node, collectionKind); 3856static NullableFlowState getResultState(BoundCollectionExpression node, CollectionExpressionTypeKind collectionKind) 3868return NullableFlowState.NotNull; 3932(int slot, NullableFlowState resultState, Func<TypeSymbol, MethodSymbol?, int>? initialStateInferenceCompletion) = 3952NullableFlowState resultState, 3981NullableFlowState resultState) 3983Debug.Assert(resultState == NullableFlowState.NotNull); 4015(int slot, NullableFlowState resultState, Func<TypeSymbol, MethodSymbol?, int>? completion) inferInitialObjectState( 4023return (-1, NullableFlowState.NotNull, inferInitialObjectStateAsContinuation(node, arguments, argumentResults, hasObjectInitializer)); 4029var resultState = NullableFlowState.NotNull; 4061resultState = NullableFlowState.MaybeNull; 4096Debug.Assert(resultState == NullableFlowState.NotNull); 4230var result = new VisitResult(objectInitializer.Type, NullableAnnotation.NotAnnotated, NullableFlowState.NotNull); 4419SetAnalyzedNullability(node.ImplicitReceiverOpt, new VisitResult(node.ImplicitReceiverOpt.Type, NullableAnnotation.NotAnnotated, NullableFlowState.NotNull)); 4476SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 4481var resultType = TypeWithState.Create(node.Type, NullableFlowState.NotNull); 4589SetResultType(node, TypeWithState.Create(anonymousType, NullableFlowState.NotNull)); 4621SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 4626SetResultType(node, TypeWithState.Create(arrayType, NullableFlowState.NotNull)); 4702var elementState = BestTypeInferrer.GetNullableState(expressionTypes); 4903NullableFlowState resultState = NullableFlowState.NotNull; 4931resultState = NullableFlowState.MaybeNull; // Delegate removal can produce null. 4934resultState = NullableFlowState.NotNull; 5466SetState(ref stateToUpdate, slot, NullableFlowState.NotNull); 5495SetState(ref state, slot, NullableFlowState.NotNull); 5520if (GetState(ref state, slot) == NullableFlowState.NotNull) 5523SetState(ref state, slot, NullableFlowState.MaybeNull); 5552SetState(ref state, childSlot, NullableFlowState.NotNull); 5631SetState(ref this.State, leftSlot, NullableFlowState.NotNull); 5686BoundNullCoalescingOperatorResultKind.NoCommonType => (node.Type, NullableFlowState.NotNull), 5691BoundNullCoalescingOperatorResultKind.RightDynamicType => (rightResultType!, NullableFlowState.NotNull), 5698(TypeSymbol ResultType, NullableFlowState LeftState) getLeftResultType(TypeSymbol leftType, TypeSymbol rightType) 5708return (rightType, NullableFlowState.NotNull); 5713return (leftType, NullableFlowState.NotNull); 5716(TypeSymbol ResultType, NullableFlowState LeftState) getResultStateWithRightType(TypeSymbol leftType, TypeSymbol rightType) 5728TypeWithState.Create(leftType, NullableFlowState.NotNull), 5739return (rightType, NullableFlowState.NotNull); 5911SetResultType(node, TypeWithState.Create(resultType, NullableFlowState.MaybeDefault)); 5966var rValueState = consequenceRValue.State.Join(alternativeRValue.State); 6074NullableFlowState resultState; 6234SetResultType(node, TypeWithState.Create(rvalueType, NullableFlowState.NotNull)); 6563private NullableFlowState LearnFromCompareExchangeMethod(in CompareExchangeInfo compareExchangeInfo) 6583return NullableFlowState.NotNull; 6593var valueFlowState = compareExchangeInfo.Results[valueIndex].RValueType.State; 6600var locationFlowState = compareExchangeInfo.Results[locationIndex].RValueType.State; 6712return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 6717return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7277SetState(ref state, memberSlot, NullableFlowState.NotNull); 7582var adjustedState = LearnFromCompareExchangeMethod(in compareExchangeInfoOpt); 7706return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7712return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 7727return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7731return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 7746return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7750return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 8224NullableFlowState state = GetState(ref this.State, slot); 8497SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 8504SetState(ref this.State, slot, NullableFlowState.NotNull); 8522SetResultType(node, TypeWithState.Create(tupleOpt, NullableFlowState.NotNull)); 8644SetState(ref this.State, targetFieldSlot, NullableFlowState.NotNull); 8661SetState(ref this.State, targetFieldSlot, NullableFlowState.NotNull); 8897NullableFlowState resultState = NullableFlowState.NotNull; 8929resultState = NullableFlowState.NotNull; 8953return TypeWithState.Create(targetType, NullableFlowState.NotNull); 8959resultState = NullableFlowState.NotNull; 8963resultState = NullableFlowState.NotNull; 8968resultState = NullableFlowState.NotNull; 9008resultState = NullableFlowState.NotNull; 9132resultState = NullableFlowState.NotNull; 9202static TypeWithState calculateResultType(TypeWithAnnotations targetTypeWithNullability, bool fromExplicitCast, NullableFlowState resultState, bool isSuppressed, TypeSymbol targetType) 9206resultState = NullableFlowState.NotNull; 9211resultState = targetType?.IsTypeParameterDisallowingAnnotationInCSharp8() == true ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9218static NullableFlowState getReferenceConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType) 9220var state = operandType.State; 9223case NullableFlowState.MaybeNull: 9229return NullableFlowState.MaybeDefault; 9235return (annotation == NullableAnnotation.Annotated) ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9239case NullableFlowState.MaybeDefault: 9242return NullableFlowState.MaybeNull; 9252static NullableFlowState getBoxingConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType) 9254var state = operandType.State; 9255if (state == NullableFlowState.MaybeNull) 9260return NullableFlowState.MaybeDefault; 9270return (annotation == NullableAnnotation.Annotated) ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9280static NullableFlowState getUnboxingConversionResultState(TypeWithState operandType) 9282var state = operandType.State; 9283if (state == NullableFlowState.MaybeNull) 9285return NullableFlowState.MaybeDefault; 9290static NullableFlowState getConversionResultState(TypeWithState operandType) 9292var state = operandType.State; 9293if (state == NullableFlowState.MaybeNull) 9295return NullableFlowState.MaybeDefault; 9423var resultType = TypeWithState.Create(targetType, NullableFlowState.NotNull); 9466NullableFlowState operandState = operandType.State; 9586private TypeWithState GetLiftedReturnType(TypeWithAnnotations returnType, NullableFlowState operandState) 9590NullableFlowState state = returnType.ToTypeWithState().State.Join(operandState); 9607private TypeWithState GetLiftedReturnTypeIfNecessary(bool isLifted, TypeWithAnnotations returnType, NullableFlowState operandState) 9703var result = TypeWithState.Create(delegateType, NullableFlowState.NotNull); 9988var rvalueResult = TypeWithState.Create(node.Type, NullableFlowState.NotNull); 10391var valueBeforeNullableWrapping = TypeWithState.Create(underlyingType.Type, NullableFlowState.NotNull); 10855var state = GetState(ref this.State, slot); 10867SetState(ref this.StateWhenTrue, containingSlot, NullableFlowState.NotNull); 11085if (enumeratorReturnType.State != NullableFlowState.NotNull) 11166var state = NullableFlowState.NotNull; 11362TypeWithState.Create(node.Type, node.OperatorKind.IsLifted() ? argumentResult.State : NullableFlowState.NotNull); 11409return TypeWithState.Create(node.Type, NullableFlowState.NotNull); 11527SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 11549SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.MaybeDefault)); 11564SetState(ref this.State, slot, NullableFlowState.NotNull); 11610NullableFlowState resultState = NullableFlowState.NotNull; 11625resultState = NullableFlowState.MaybeDefault; 11663SetResultType(node, TypeWithState.Create(node.Type, node.Type?.CanContainNull() != false && node.ConstantValueOpt?.IsNull == true ? NullableFlowState.MaybeDefault : NullableFlowState.NotNull)); 11771node.IsAddition ? GetState(ref this.State, memberSlot).Meet(ResultType.State) : NullableFlowState.MaybeNull); 11888private bool ReportPossibleNullReceiverIfNeeded(TypeSymbol type, NullableFlowState state, bool checkNullableValueType, SyntaxNode syntax, out bool reportedDiagnostic) 11947SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 11962SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12011SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12017SetResultType(node, TypeWithState.Create(type, NullableFlowState.NotNull)); 12085SetState(ref this.State, slot, NullableFlowState.NotNull); 12174Debug.Assert(ResultType is TypeWithState { Type: FunctionPointerTypeSymbol { }, State: NullableFlowState.NotNull }); 12479SetValue(Id, index, useNotNullsAsDefault ? NullableFlowState.NotNull : walker.GetDefaultState(ref this, slot)); 12483public NullableFlowState this[int slot] 12497private NullableFlowState GetValue(int id, int index) 12507private NullableFlowState GetValue(int index) 12511return NullableFlowState.NotNull; 12518var result = (_state[index], _state[index + 1]) switch 12520(false, false) => NullableFlowState.NotNull, // Should not be reachable 12521(true, false) => NullableFlowState.MaybeNull, 12522(false, true) => NullableFlowState.MaybeDefault, 12523(true, true) => NullableFlowState.NotNull 12529private void SetValue(int id, int index, NullableFlowState value) 12542private void SetValue(int index, NullableFlowState value) 12550NullableFlowState.MaybeNull => (true, false), 12551NullableFlowState.MaybeDefault => (false, true), 12552NullableFlowState.NotNull => (true, true), 12606var oldValue = oldReachable ? GetValue(i) : NullableFlowState.NotNull; 12607var newValue = oldValue.Join(other.GetValue(i)); 12632var oldValue = GetValue(i); 12633var newValue = oldValue.Meet(other.GetValue(i)); 12649var mayBeNull = GetValue(i) is NullableFlowState.MaybeNull or NullableFlowState.MaybeDefault; 12680NullableFlowState.MaybeNull => "?", 12681NullableFlowState.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;