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); 791var memberState = GetState(ref state, slot); 792var badState = symbolType.Type.IsPossiblyNullableReferenceTypeTypeParameter() && (annotations & FlowAnalysisAnnotations.NotNull) == 0 793? NullableFlowState.MaybeDefault 794: NullableFlowState.MaybeNull; 850SetState(ref this.State, memberSlot, type.Type.IsPossiblyNullableReferenceTypeTypeParameter() ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull); 1145var parameterState = GetState(ref state, memberSlot); 1177SetState(ref this.State, memberSlot, NullableFlowState.MaybeNull); 1279var parameterState = GetState(ref state, slot); 1335var parameterState = GetState(ref stateWhen, slot); 1362private void EnforceNotNullIfNotNull(SyntaxNode? syntaxOpt, LocalState state, ImmutableArray<ParameterSymbol> parameters, ImmutableHashSet<string> inputParamNames, NullableFlowState outputState, ParameterSymbol? outputParam) 1949private NullableFlowState GetState(ref LocalState state, int slot) 1952return NullableFlowState.NotNull; 1958private void SetState(ref LocalState state, int slot, NullableFlowState value, bool useNotNullsAsDefault = false) 1980private NullableFlowState GetDefaultState(ref LocalState state, int slot) 1985return NullableFlowState.NotNull; 2015return NullableFlowState.NotNull; 2344private static bool ShouldReportNullableAssignment(TypeWithAnnotations type, NullableFlowState state) 2361case NullableFlowState.NotNull: 2363case NullableFlowState.MaybeNull: 2439valueType.State == NullableFlowState.MaybeDefault; 2621var newState = valueType.State; 2721NullableFlowState value = isDefaultValue ? NullableFlowState.MaybeNull : fieldOrPropertyType.ToTypeWithState().State; 2733NullableFlowState.NotNull; 2765/// and the new state is not <see cref="NullableFlowState.NotNull"/>, this method should be called to perform the 2769private void SetStateAndTrackForFinally(ref LocalState state, int slot, NullableFlowState newState) 2773if (newState != NullableFlowState.NotNull && NonMonotonicState.HasValue) 2851private NullableFlowState GetDefaultState(Symbol symbol) 2944var state = GetParameterState(parameterType, parameter.FlowAnalysisAnnotations).State; 2982return TypeWithState.Create(parameterType.Type, NullableFlowState.MaybeDefault); 2987return TypeWithState.Create(parameterType.Type, NullableFlowState.NotNull); 3290SetState(ref state, slot, NullableFlowState.NotNull); 3789SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 3797SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 3902NullableFlowState resultState = getResultState(node, collectionKind); 3908static NullableFlowState getResultState(BoundCollectionExpression node, CollectionExpressionTypeKind collectionKind) 3920return NullableFlowState.NotNull; 3984(int slot, NullableFlowState resultState, Func<TypeSymbol, MethodSymbol?, int>? initialStateInferenceCompletion) = 4004NullableFlowState resultState, 4033NullableFlowState resultState) 4035Debug.Assert(resultState == NullableFlowState.NotNull); 4067(int slot, NullableFlowState resultState, Func<TypeSymbol, MethodSymbol?, int>? completion) inferInitialObjectState( 4075return (-1, NullableFlowState.NotNull, inferInitialObjectStateAsContinuation(node, arguments, argumentResults, hasObjectInitializer)); 4081var resultState = NullableFlowState.NotNull; 4113resultState = NullableFlowState.MaybeNull; 4148Debug.Assert(resultState == NullableFlowState.NotNull); 4282var result = new VisitResult(objectInitializer.Type, NullableAnnotation.NotAnnotated, NullableFlowState.NotNull); 4471SetAnalyzedNullability(node.ImplicitReceiverOpt, new VisitResult(node.ImplicitReceiverOpt.Type, NullableAnnotation.NotAnnotated, NullableFlowState.NotNull)); 4528SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 4533var resultType = TypeWithState.Create(node.Type, NullableFlowState.NotNull); 4641SetResultType(node, TypeWithState.Create(anonymousType, NullableFlowState.NotNull)); 4673SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 4678SetResultType(node, TypeWithState.Create(arrayType, NullableFlowState.NotNull)); 4754var elementState = BestTypeInferrer.GetNullableState(expressionTypes); 4956NullableFlowState resultState = NullableFlowState.NotNull; 4984resultState = NullableFlowState.MaybeNull; // Delegate removal can produce null. 4987resultState = NullableFlowState.NotNull; 5519SetState(ref stateToUpdate, slot, NullableFlowState.NotNull); 5548SetState(ref state, slot, NullableFlowState.NotNull); 5573if (GetState(ref state, slot) == NullableFlowState.NotNull) 5576SetState(ref state, slot, NullableFlowState.MaybeNull); 5605SetState(ref state, childSlot, NullableFlowState.NotNull); 5684SetState(ref this.State, leftSlot, NullableFlowState.NotNull); 5739BoundNullCoalescingOperatorResultKind.NoCommonType => (node.Type, NullableFlowState.NotNull), 5744BoundNullCoalescingOperatorResultKind.RightDynamicType => (rightResultType!, NullableFlowState.NotNull), 5751(TypeSymbol ResultType, NullableFlowState LeftState) getLeftResultType(TypeSymbol leftType, TypeSymbol rightType) 5761return (rightType, NullableFlowState.NotNull); 5766return (leftType, NullableFlowState.NotNull); 5769(TypeSymbol ResultType, NullableFlowState LeftState) getResultStateWithRightType(TypeSymbol leftType, TypeSymbol rightType) 5781TypeWithState.Create(leftType, NullableFlowState.NotNull), 5792return (rightType, NullableFlowState.NotNull); 5964SetResultType(node, TypeWithState.Create(resultType, NullableFlowState.MaybeDefault)); 6019var rValueState = consequenceRValue.State.Join(alternativeRValue.State); 6127NullableFlowState resultState; 6287SetResultType(node, TypeWithState.Create(rvalueType, NullableFlowState.NotNull)); 6616private NullableFlowState LearnFromCompareExchangeMethod(in CompareExchangeInfo compareExchangeInfo) 6636return NullableFlowState.NotNull; 6646var valueFlowState = compareExchangeInfo.Results[valueIndex].RValueType.State; 6653var locationFlowState = compareExchangeInfo.Results[locationIndex].RValueType.State; 6765return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 6770return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7330SetState(ref state, memberSlot, NullableFlowState.NotNull); 7635var adjustedState = LearnFromCompareExchangeMethod(in compareExchangeInfoOpt); 7759return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7765return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 7780return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7784return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 7799return TypeWithState.Create(typeWithState.Type, NullableFlowState.MaybeDefault); 7803return TypeWithState.Create(typeWithState.Type, NullableFlowState.NotNull); 8277NullableFlowState state = GetState(ref this.State, slot); 8550SetResultType(node, TypeWithState.Create(null, NullableFlowState.NotNull)); 8557SetState(ref this.State, slot, NullableFlowState.NotNull); 8575SetResultType(node, TypeWithState.Create(tupleOpt, NullableFlowState.NotNull)); 8697SetState(ref this.State, targetFieldSlot, NullableFlowState.NotNull); 8714SetState(ref this.State, targetFieldSlot, NullableFlowState.NotNull); 8950NullableFlowState resultState = NullableFlowState.NotNull; 8982resultState = NullableFlowState.NotNull; 9006return TypeWithState.Create(targetType, NullableFlowState.NotNull); 9012resultState = NullableFlowState.NotNull; 9016resultState = NullableFlowState.NotNull; 9021resultState = NullableFlowState.NotNull; 9061resultState = NullableFlowState.NotNull; 9185resultState = NullableFlowState.NotNull; 9255static TypeWithState calculateResultType(TypeWithAnnotations targetTypeWithNullability, bool fromExplicitCast, NullableFlowState resultState, bool isSuppressed, TypeSymbol targetType) 9259resultState = NullableFlowState.NotNull; 9264resultState = targetType?.IsTypeParameterDisallowingAnnotationInCSharp8() == true ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9271static NullableFlowState getReferenceConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType) 9273var state = operandType.State; 9276case NullableFlowState.MaybeNull: 9282return NullableFlowState.MaybeDefault; 9288return (annotation == NullableAnnotation.Annotated) ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9292case NullableFlowState.MaybeDefault: 9295return NullableFlowState.MaybeNull; 9305static NullableFlowState getBoxingConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType) 9307var state = operandType.State; 9308if (state == NullableFlowState.MaybeNull) 9313return NullableFlowState.MaybeDefault; 9323return (annotation == NullableAnnotation.Annotated) ? NullableFlowState.MaybeDefault : NullableFlowState.MaybeNull; 9333static NullableFlowState getUnboxingConversionResultState(TypeWithState operandType) 9335var state = operandType.State; 9336if (state == NullableFlowState.MaybeNull) 9338return NullableFlowState.MaybeDefault; 9343static NullableFlowState getConversionResultState(TypeWithState operandType) 9345var state = operandType.State; 9346if (state == NullableFlowState.MaybeNull) 9348return NullableFlowState.MaybeDefault; 9476var resultType = TypeWithState.Create(targetType, NullableFlowState.NotNull); 9519NullableFlowState operandState = operandType.State; 9639private TypeWithState GetLiftedReturnType(TypeWithAnnotations returnType, NullableFlowState operandState) 9643NullableFlowState state = returnType.ToTypeWithState().State.Join(operandState); 9660private TypeWithState GetLiftedReturnTypeIfNecessary(bool isLifted, TypeWithAnnotations returnType, NullableFlowState operandState) 9756var result = TypeWithState.Create(delegateType, NullableFlowState.NotNull); 10041var rvalueResult = TypeWithState.Create(node.Type, NullableFlowState.NotNull); 10458var valueBeforeNullableWrapping = TypeWithState.Create(underlyingType.Type, NullableFlowState.NotNull); 10922var state = GetState(ref this.State, slot); 10934SetState(ref this.StateWhenTrue, containingSlot, NullableFlowState.NotNull); 11152if (enumeratorReturnType.State != NullableFlowState.NotNull) 11233var state = NullableFlowState.NotNull; 11429TypeWithState.Create(node.Type, node.OperatorKind.IsLifted() ? argumentResult.State : NullableFlowState.NotNull); 11476return TypeWithState.Create(node.Type, NullableFlowState.NotNull); 11594SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 11616SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.MaybeDefault)); 11631SetState(ref this.State, slot, NullableFlowState.NotNull); 11677NullableFlowState resultState = NullableFlowState.NotNull; 11692resultState = NullableFlowState.MaybeDefault; 11730SetResultType(node, TypeWithState.Create(node.Type, node.Type?.CanContainNull() != false && node.ConstantValueOpt?.IsNull == true ? NullableFlowState.MaybeDefault : NullableFlowState.NotNull)); 11838node.IsAddition ? GetState(ref this.State, memberSlot).Meet(ResultType.State) : NullableFlowState.MaybeNull); 11955private bool ReportPossibleNullReceiverIfNeeded(TypeSymbol type, NullableFlowState state, bool checkNullableValueType, SyntaxNode syntax, out bool reportedDiagnostic) 12014SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12029SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12078SetResultType(node, TypeWithState.Create(node.Type, NullableFlowState.NotNull)); 12084SetResultType(node, TypeWithState.Create(type, NullableFlowState.NotNull)); 12152SetState(ref this.State, slot, NullableFlowState.NotNull); 12241Debug.Assert(ResultType is TypeWithState { Type: FunctionPointerTypeSymbol { }, State: NullableFlowState.NotNull }); 12546SetValue(Id, index, useNotNullsAsDefault ? NullableFlowState.NotNull : walker.GetDefaultState(ref this, slot)); 12550public NullableFlowState this[int slot] 12564private NullableFlowState GetValue(int id, int index) 12574private NullableFlowState GetValue(int index) 12578return NullableFlowState.NotNull; 12585var result = (_state[index], _state[index + 1]) switch 12587(false, false) => NullableFlowState.NotNull, // Should not be reachable 12588(true, false) => NullableFlowState.MaybeNull, 12589(false, true) => NullableFlowState.MaybeDefault, 12590(true, true) => NullableFlowState.NotNull 12596private void SetValue(int id, int index, NullableFlowState value) 12609private void SetValue(int index, NullableFlowState value) 12617NullableFlowState.MaybeNull => (true, false), 12618NullableFlowState.MaybeDefault => (false, true), 12619NullableFlowState.NotNull => (true, true), 12673var oldValue = oldReachable ? GetValue(i) : NullableFlowState.NotNull; 12674var newValue = oldValue.Join(other.GetValue(i)); 12699var oldValue = GetValue(i); 12700var newValue = oldValue.Meet(other.GetValue(i)); 12716var mayBeNull = GetValue(i) is NullableFlowState.MaybeNull or NullableFlowState.MaybeDefault; 12747NullableFlowState.MaybeNull => "?", 12748NullableFlowState.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;