310 references to NullableFlowState
Microsoft.CodeAnalysis.CSharp (268)
Binder\Semantics\BestTypeInferrer.cs (3)
36
public static
NullableFlowState
GetNullableState(ArrayBuilder<TypeWithState> types)
38
NullableFlowState
result =
NullableFlowState
.NotNull;
FlowAnalysis\NullableWalker.cs (193)
126
public VisitResult(TypeSymbol? type, NullableAnnotation annotation,
NullableFlowState
state)
216
private static readonly TypeWithState _invalidType = TypeWithState.Create(new UnsupportedMetadataTypeSymbol(),
NullableFlowState
.NotNull);
802
var
memberState = GetState(ref state, slot);
803
var
badState = symbolType.Type.IsPossiblyNullableReferenceTypeTypeParameter() && (annotations & FlowAnalysisAnnotations.NotNull) == 0
804
?
NullableFlowState
.MaybeDefault
805
:
NullableFlowState
.MaybeNull;
861
SetState(ref this.State, memberSlot, type.Type.IsPossiblyNullableReferenceTypeTypeParameter() ?
NullableFlowState
.MaybeDefault :
NullableFlowState
.MaybeNull);
1156
var
parameterState = GetState(ref state, memberSlot);
1188
SetState(ref this.State, memberSlot,
NullableFlowState
.MaybeNull);
1301
var
parameterState = GetState(ref state, slot);
1357
var
parameterState = GetState(ref stateWhen, slot);
1384
private void EnforceNotNullIfNotNull(SyntaxNode? syntaxOpt, LocalState state, ImmutableArray<ParameterSymbol> parameters, ImmutableHashSet<string> inputParamNames,
NullableFlowState
outputState, ParameterSymbol? outputParam)
1971
private
NullableFlowState
GetState(ref LocalState state, int slot)
1974
return
NullableFlowState
.NotNull;
1980
private void SetState(ref LocalState state, int slot,
NullableFlowState
value, bool useNotNullsAsDefault = false)
2002
private
NullableFlowState
GetDefaultState(ref LocalState state, int slot)
2007
return
NullableFlowState
.NotNull;
2037
return
NullableFlowState
.NotNull;
2366
private static bool ShouldReportNullableAssignment(TypeWithAnnotations type,
NullableFlowState
state)
2383
case
NullableFlowState
.NotNull:
2385
case
NullableFlowState
.MaybeNull:
2461
valueType.State ==
NullableFlowState
.MaybeDefault;
2643
var
newState = valueType.State;
2746
NullableFlowState
value = isDefaultValue ?
NullableFlowState
.MaybeNull : fieldOrPropertyType.ToTypeWithState().State;
2758
NullableFlowState
.NotNull;
2806
/// and the new state is not <see cref="
NullableFlowState
.NotNull"/>, this method should be called to perform the
2810
private void SetStateAndTrackForFinally(ref LocalState state, int slot,
NullableFlowState
newState)
2814
if (newState !=
NullableFlowState
.NotNull && NonMonotonicState.HasValue)
2899
private
NullableFlowState
GetDefaultState(Symbol symbol)
2992
var
state = GetParameterState(parameterType, parameter.FlowAnalysisAnnotations).State;
3030
return TypeWithState.Create(parameterType.Type,
NullableFlowState
.MaybeDefault);
3035
return TypeWithState.Create(parameterType.Type,
NullableFlowState
.NotNull);
3339
SetState(ref state, slot,
NullableFlowState
.NotNull);
3838
SetResultType(node, TypeWithState.Create(null,
NullableFlowState
.NotNull));
3846
SetResultType(node, TypeWithState.Create(null,
NullableFlowState
.NotNull));
4000
NullableFlowState
resultState = getResultState(node, collectionKind);
4006
static
NullableFlowState
getResultState(BoundCollectionExpression node, CollectionExpressionTypeKind collectionKind)
4018
return
NullableFlowState
.NotNull;
4087
(int slot,
NullableFlowState
resultState, Func<TypeSymbol, MethodSymbol?, int>? initialStateInferenceCompletion) =
4107
NullableFlowState
resultState,
4136
NullableFlowState
resultState)
4138
Debug.Assert(resultState ==
NullableFlowState
.NotNull);
4170
(int slot,
NullableFlowState
resultState, Func<TypeSymbol, MethodSymbol?, int>? completion) inferInitialObjectState(
4178
return (-1,
NullableFlowState
.NotNull, inferInitialObjectStateAsContinuation(node, arguments, argumentResults, hasObjectInitializer));
4184
var
resultState =
NullableFlowState
.NotNull;
4216
resultState =
NullableFlowState
.MaybeNull;
4251
Debug.Assert(resultState ==
NullableFlowState
.NotNull);
4385
var result = new VisitResult(objectInitializer.Type, NullableAnnotation.NotAnnotated,
NullableFlowState
.NotNull);
4575
SetAnalyzedNullability(node.ImplicitReceiverOpt, new VisitResult(node.ImplicitReceiverOpt.Type, NullableAnnotation.NotAnnotated,
NullableFlowState
.NotNull));
4633
SetResultType(node, TypeWithState.Create(node.Type,
NullableFlowState
.NotNull));
4638
var resultType = TypeWithState.Create(node.Type,
NullableFlowState
.NotNull);
4746
SetResultType(node, TypeWithState.Create(anonymousType,
NullableFlowState
.NotNull));
4778
SetResultType(node, TypeWithState.Create(node.Type,
NullableFlowState
.NotNull));
4783
SetResultType(node, TypeWithState.Create(arrayType,
NullableFlowState
.NotNull));
4859
var
elementState = BestTypeInferrer.GetNullableState(expressionTypes);
5061
NullableFlowState
resultState =
NullableFlowState
.NotNull;
5089
resultState =
NullableFlowState
.MaybeNull; // Delegate removal can produce null.
5092
resultState =
NullableFlowState
.NotNull;
5681
SetState(ref stateToUpdate, slot,
NullableFlowState
.NotNull);
5710
SetState(ref state, slot,
NullableFlowState
.NotNull);
5735
if (GetState(ref state, slot) ==
NullableFlowState
.NotNull)
5738
SetState(ref state, slot,
NullableFlowState
.MaybeNull);
5767
SetState(ref state, childSlot,
NullableFlowState
.NotNull);
5846
SetState(ref this.State, leftSlot,
NullableFlowState
.NotNull);
5901
BoundNullCoalescingOperatorResultKind.NoCommonType => (node.Type,
NullableFlowState
.NotNull),
5906
BoundNullCoalescingOperatorResultKind.RightDynamicType => (rightResultType!,
NullableFlowState
.NotNull),
5913
(TypeSymbol ResultType,
NullableFlowState
LeftState) getLeftResultType(TypeSymbol leftType, TypeSymbol rightType)
5923
return (rightType,
NullableFlowState
.NotNull);
5928
return (leftType,
NullableFlowState
.NotNull);
5931
(TypeSymbol ResultType,
NullableFlowState
LeftState) getResultStateWithRightType(TypeSymbol leftType, TypeSymbol rightType)
5943
TypeWithState.Create(leftType,
NullableFlowState
.NotNull),
5954
return (rightType,
NullableFlowState
.NotNull);
6127
SetResultType(node, TypeWithState.Create(resultType,
NullableFlowState
.MaybeDefault));
6182
var
rValueState = consequenceRValue.State.Join(alternativeRValue.State);
6290
NullableFlowState
resultState;
6450
SetResultType(node, TypeWithState.Create(rvalueType,
NullableFlowState
.NotNull));
6919
private
NullableFlowState
LearnFromCompareExchangeMethod(in CompareExchangeInfo compareExchangeInfo)
6939
return
NullableFlowState
.NotNull;
6949
var
valueFlowState = compareExchangeInfo.Results[valueIndex].RValueType.State;
6956
var
locationFlowState = compareExchangeInfo.Results[locationIndex].RValueType.State;
7073
return TypeWithState.Create(typeWithState.Type,
NullableFlowState
.NotNull);
7078
return TypeWithState.Create(typeWithState.Type,
NullableFlowState
.MaybeDefault);
7663
SetState(ref state, memberSlot,
NullableFlowState
.NotNull);
7968
var
adjustedState = LearnFromCompareExchangeMethod(in compareExchangeInfoOpt);
8092
return TypeWithState.Create(typeWithState.Type,
NullableFlowState
.MaybeDefault);
8098
return TypeWithState.Create(typeWithState.Type,
NullableFlowState
.NotNull);
8113
return TypeWithState.Create(typeWithState.Type,
NullableFlowState
.MaybeDefault);
8117
return TypeWithState.Create(typeWithState.Type,
NullableFlowState
.NotNull);
8132
return TypeWithState.Create(typeWithState.Type,
NullableFlowState
.MaybeDefault);
8136
return TypeWithState.Create(typeWithState.Type,
NullableFlowState
.NotNull);
8648
NullableFlowState
state = GetState(ref this.State, slot);
8923
SetResultType(node, TypeWithState.Create(null,
NullableFlowState
.NotNull));
8930
SetState(ref this.State, slot,
NullableFlowState
.NotNull);
8948
SetResultType(node, TypeWithState.Create(tupleOpt,
NullableFlowState
.NotNull));
9070
SetState(ref this.State, targetFieldSlot,
NullableFlowState
.NotNull);
9087
SetState(ref this.State, targetFieldSlot,
NullableFlowState
.NotNull);
9323
NullableFlowState
resultState =
NullableFlowState
.NotNull;
9355
resultState =
NullableFlowState
.NotNull;
9379
return TypeWithState.Create(targetType,
NullableFlowState
.NotNull);
9385
resultState =
NullableFlowState
.NotNull;
9389
resultState =
NullableFlowState
.NotNull;
9394
resultState =
NullableFlowState
.NotNull;
9434
resultState =
NullableFlowState
.NotNull;
9558
resultState =
NullableFlowState
.NotNull;
9628
static TypeWithState calculateResultType(TypeWithAnnotations targetTypeWithNullability, bool fromExplicitCast,
NullableFlowState
resultState, bool isSuppressed, TypeSymbol targetType)
9632
resultState =
NullableFlowState
.NotNull;
9637
resultState = targetType?.IsTypeParameterDisallowingAnnotationInCSharp8() == true ?
NullableFlowState
.MaybeDefault :
NullableFlowState
.MaybeNull;
9644
static
NullableFlowState
getReferenceConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType)
9646
var
state = operandType.State;
9649
case
NullableFlowState
.MaybeNull:
9655
return
NullableFlowState
.MaybeDefault;
9661
return (annotation == NullableAnnotation.Annotated) ?
NullableFlowState
.MaybeDefault :
NullableFlowState
.MaybeNull;
9665
case
NullableFlowState
.MaybeDefault:
9668
return
NullableFlowState
.MaybeNull;
9678
static
NullableFlowState
getBoxingConversionResultState(TypeWithAnnotations targetType, TypeWithState operandType)
9680
var
state = operandType.State;
9681
if (state ==
NullableFlowState
.MaybeNull)
9686
return
NullableFlowState
.MaybeDefault;
9696
return (annotation == NullableAnnotation.Annotated) ?
NullableFlowState
.MaybeDefault :
NullableFlowState
.MaybeNull;
9706
static
NullableFlowState
getUnboxingConversionResultState(TypeWithState operandType)
9708
var
state = operandType.State;
9709
if (state ==
NullableFlowState
.MaybeNull)
9711
return
NullableFlowState
.MaybeDefault;
9716
static
NullableFlowState
getConversionResultState(TypeWithState operandType)
9718
var
state = operandType.State;
9719
if (state ==
NullableFlowState
.MaybeNull)
9721
return
NullableFlowState
.MaybeDefault;
9857
var resultType = TypeWithState.Create(targetType,
NullableFlowState
.NotNull);
9900
NullableFlowState
operandState = operandType.State;
10020
private TypeWithState GetLiftedReturnType(TypeWithAnnotations returnType,
NullableFlowState
operandState)
10024
NullableFlowState
state = returnType.ToTypeWithState().State.Join(operandState);
10041
private TypeWithState GetLiftedReturnTypeIfNecessary(bool isLifted, TypeWithAnnotations returnType,
NullableFlowState
operandState)
10137
var result = TypeWithState.Create(delegateType,
NullableFlowState
.NotNull);
10434
var rvalueResult = TypeWithState.Create(node.Type,
NullableFlowState
.NotNull);
10854
var valueBeforeNullableWrapping = TypeWithState.Create(underlyingType.Type,
NullableFlowState
.NotNull);
10984
SetResultType(node, TypeWithState.Create(receiverType.Type,
NullableFlowState
.NotNull));
11008
SetResultType(node, TypeWithState.Create(opType.Type,
NullableFlowState
.NotNull));
11162
SetResultType(node, TypeWithState.Create(receiverType.Type,
NullableFlowState
.NotNull));
11190
SetResultType(node, TypeWithState.Create(opType.Type,
NullableFlowState
.NotNull));
11492
var
state = GetState(ref this.State, slot);
11504
SetState(ref this.StateWhenTrue, containingSlot,
NullableFlowState
.NotNull);
11728
if (enumeratorReturnType.State !=
NullableFlowState
.NotNull)
11809
var
state =
NullableFlowState
.NotNull;
12006
TypeWithState.Create(node.Type, node.OperatorKind.IsLifted() ? argumentResult.State :
NullableFlowState
.NotNull);
12274
SetResultType(node, TypeWithState.Create(node.Type,
NullableFlowState
.NotNull));
12296
SetResultType(node, TypeWithState.Create(node.Type,
NullableFlowState
.MaybeDefault));
12311
SetState(ref this.State, slot,
NullableFlowState
.NotNull);
12357
NullableFlowState
resultState =
NullableFlowState
.NotNull;
12372
resultState =
NullableFlowState
.MaybeDefault;
12410
SetResultType(node, TypeWithState.Create(node.Type, node.Type?.CanContainNull() != false && node.ConstantValueOpt?.IsNull == true ?
NullableFlowState
.MaybeDefault :
NullableFlowState
.NotNull));
12518
node.IsAddition ? GetState(ref this.State, memberSlot).Meet(ResultType.State) :
NullableFlowState
.MaybeNull);
12635
private bool ReportPossibleNullReceiverIfNeeded(TypeSymbol type,
NullableFlowState
state, bool checkNullableValueType, SyntaxNode syntax, out bool reportedDiagnostic)
12694
SetResultType(node, TypeWithState.Create(node.Type,
NullableFlowState
.NotNull));
12709
SetResultType(node, TypeWithState.Create(node.Type,
NullableFlowState
.NotNull));
12758
SetResultType(node, TypeWithState.Create(node.Type,
NullableFlowState
.NotNull));
12764
SetResultType(node, TypeWithState.Create(type,
NullableFlowState
.NotNull));
12832
SetState(ref this.State, slot,
NullableFlowState
.NotNull);
12921
Debug.Assert(ResultType is TypeWithState { Type: FunctionPointerTypeSymbol { }, State:
NullableFlowState
.NotNull });
13226
SetValue(Id, index, useNotNullsAsDefault ?
NullableFlowState
.NotNull : walker.GetDefaultState(ref this, slot));
13230
public
NullableFlowState
this[int slot]
13244
private
NullableFlowState
GetValue(int id, int index)
13254
private
NullableFlowState
GetValue(int index)
13258
return
NullableFlowState
.NotNull;
13265
var
result = (_state[index], _state[index + 1]) switch
13267
(false, false) =>
NullableFlowState
.NotNull, // Should not be reachable
13268
(true, false) =>
NullableFlowState
.MaybeNull,
13269
(false, true) =>
NullableFlowState
.MaybeDefault,
13270
(true, true) =>
NullableFlowState
.NotNull
13276
private void SetValue(int id, int index,
NullableFlowState
value)
13289
private void SetValue(int index,
NullableFlowState
value)
13297
NullableFlowState
.MaybeNull => (true, false),
13298
NullableFlowState
.MaybeDefault => (false, true),
13299
NullableFlowState
.NotNull => (true, true),
13353
var
oldValue = oldReachable ? GetValue(i) :
NullableFlowState
.NotNull;
13354
var
newValue = oldValue.Join(other.GetValue(i));
13379
var
oldValue = GetValue(i);
13380
var
newValue = oldValue.Meet(other.GetValue(i));
13396
var mayBeNull = GetValue(i) is
NullableFlowState
.MaybeNull or
NullableFlowState
.MaybeDefault;
13427
NullableFlowState
.MaybeNull => "?",
13428
NullableFlowState
.MaybeDefault => "??",
FlowAnalysis\NullableWalker_Patterns.cs (5)
481
SetState(ref State, outputSlot,
NullableFlowState
.NotNull);
579
SetState(ref this.State, outputSlot,
NullableFlowState
.NotNull); // Slice value is assumed to be never null
682
var
tempState = GetState(ref this.State, tempSlot);
958
NullableFlowState
inferredState;
1008
NullableFlowState
inferredState = BestTypeInferrer.GetNullableState(resultTypes);
Symbols\ConstraintsHelper.cs (14)
1228
static
NullableFlowState
getTypeArgumentState(in TypeWithAnnotations typeWithAnnotations)
1233
return
NullableFlowState
.NotNull;
1237
return type.IsNullableTypeOrTypeParameter() ?
NullableFlowState
.MaybeNull :
NullableFlowState
.NotNull;
1242
return type.IsTypeParameterDisallowingAnnotationInCSharp8() ?
NullableFlowState
.MaybeDefault :
NullableFlowState
.MaybeNull;
1244
return
NullableFlowState
.NotNull;
1249
return
NullableFlowState
.NotNull;
1251
NullableFlowState
? result = null;
1254
var
constraintState = getTypeArgumentState(constraintType);
1264
return result ??
NullableFlowState
.MaybeNull;
1267
static bool constraintTypeAllows(in TypeWithAnnotations typeWithAnnotations,
NullableFlowState
state)
1269
if (state ==
NullableFlowState
.NotNull)
1296
return state ==
NullableFlowState
.MaybeNull;
Symbols\NullableAnnotationExtensions.cs (1)
104
var
flowState = TypeWithAnnotations.Create(type, annotation).ToTypeWithState().State;
Symbols\NullableFlowState.cs (1)
11
/// When in doubt we conservatively use <see cref="
NullableFlowState
.NotNull"/>
Symbols\NullableFlowStateExtensions.cs (20)
13
public static bool MayBeNull(this
NullableFlowState
state) => state !=
NullableFlowState
.NotNull;
15
public static bool IsNotNull(this
NullableFlowState
state) => state ==
NullableFlowState
.NotNull;
19
/// The result is <see cref="
NullableFlowState
.MaybeNull"/> if either operand is that.
21
public 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.
27
public static
NullableFlowState
Meet(this
NullableFlowState
a,
NullableFlowState
b) => (a < b) ? a : b;
29
internal static CodeAnalysis.NullableFlowState ToPublicFlowState(this CSharp.
NullableFlowState
nullableFlowState) =>
32
CSharp.
NullableFlowState
.NotNull => CodeAnalysis.NullableFlowState.NotNull,
33
CSharp.
NullableFlowState
.MaybeNull => CodeAnalysis.NullableFlowState.MaybeNull,
34
CSharp.
NullableFlowState
.MaybeDefault => CodeAnalysis.NullableFlowState.MaybeNull,
39
public static CSharp.
NullableFlowState
ToInternalFlowState(this CodeAnalysis.NullableFlowState flowState) =>
42
CodeAnalysis.NullableFlowState.None => CSharp.
NullableFlowState
.NotNull,
43
CodeAnalysis.NullableFlowState.NotNull => CSharp.
NullableFlowState
.NotNull,
44
CodeAnalysis.NullableFlowState.MaybeNull => CSharp.
NullableFlowState
.MaybeNull,
Symbols\TypeWithAnnotations.cs (11)
813
static
NullableFlowState
getFlowState(TypeSymbol type, NullableAnnotation annotation)
817
return annotation.IsAnnotated() ?
NullableFlowState
.MaybeDefault :
NullableFlowState
.NotNull;
821
return annotation switch { NullableAnnotation.Annotated =>
NullableFlowState
.MaybeDefault, NullableAnnotation.NotAnnotated =>
NullableFlowState
.MaybeNull, _ =>
NullableFlowState
.NotNull };
825
return annotation switch { NullableAnnotation.Annotated =>
NullableFlowState
.MaybeDefault, _ =>
NullableFlowState
.NotNull };
829
return
NullableFlowState
.MaybeNull;
831
return annotation switch { NullableAnnotation.Annotated =>
NullableFlowState
.MaybeNull, _ =>
NullableFlowState
.NotNull };
Symbols\TypeWithState.cs (20)
17
public readonly
NullableFlowState
State;
20
public bool MayBeNull => State ==
NullableFlowState
.MaybeNull;
21
public bool IsNotNull => State ==
NullableFlowState
.NotNull;
25
return Create(type,
NullableFlowState
.MaybeDefault);
28
public static TypeWithState Create(TypeSymbol? type,
NullableFlowState
defaultState)
30
if (defaultState ==
NullableFlowState
.MaybeDefault &&
36
var
state = defaultState !=
NullableFlowState
.NotNull && type?.CanContainNull() != false ?
NullableFlowState
.MaybeNull :
NullableFlowState
.NotNull;
45
NullableFlowState
state;
50
state =
NullableFlowState
.MaybeDefault;
54
state =
NullableFlowState
.NotNull;
63
state =
NullableFlowState
.NotNull;
69
private TypeWithState(TypeSymbol? type,
NullableFlowState
state)
71
Debug.Assert(state ==
NullableFlowState
.NotNull || type?.CanContainNull() != false);
72
Debug.Assert(state !=
NullableFlowState
.MaybeDefault || type is null || type.IsTypeParameterDisallowingAnnotationInCSharp8());
81
public TypeWithState WithNotNullState() => new TypeWithState(Type,
NullableFlowState
.NotNull);
83
public TypeWithState WithSuppression(bool suppress) => suppress ? new TypeWithState(Type,
NullableFlowState
.NotNull) : this;
90
return (State ==
NullableFlowState
.MaybeDefault || asAnnotatedType) ? type.SetIsAnnotated(compilation) : type;
Microsoft.CodeAnalysis.CSharp.Semantic.UnitTests (42)
Semantics\NullableReferenceTypesTests.cs (42)
126877
private static readonly
NullableFlowState
[] s_AllNullableFlowStates = (
NullableFlowState
[])Enum.GetValues(typeof(
NullableFlowState
));
126898
var inputs = new[] {
NullableFlowState
.NotNull,
NullableFlowState
.MaybeNull };
126900
Func<int, int,
NullableFlowState
> getResult = (i, j) => inputs[i].Join(inputs[j]);
126902
var expected = new
NullableFlowState
[2, 2]
126904
{
NullableFlowState
.NotNull,
NullableFlowState
.MaybeNull },
126905
{
NullableFlowState
.MaybeNull,
NullableFlowState
.MaybeNull },
126930
var inputs = new[] {
NullableFlowState
.NotNull,
NullableFlowState
.MaybeNull };
126931
Func<int, int,
NullableFlowState
> getResult = (i, j) => inputs[i].Meet(inputs[j]);
126933
var expected = new
NullableFlowState
[2, 2]
126935
{
NullableFlowState
.NotNull,
NullableFlowState
.NotNull },
126936
{
NullableFlowState
.NotNull,
NullableFlowState
.MaybeNull },
126963
private static void AssertEqual(
NullableFlowState
[,] expected, Func<int, int,
NullableFlowState
> getResult, int size)
126965
AssertEx.Equal<
NullableFlowState
>(expected, getResult, (na1, na2) => na1 == na2, na => $"NullableFlowState.{na}", "{0,-32:G}", size);
126984
foreach (
var
a in s_AllNullableFlowStates)
126986
foreach (
var
b in s_AllNullableFlowStates)
127014
foreach (
var
a in s_AllNullableFlowStates)
127016
foreach (
var
b in s_AllNullableFlowStates)
127018
foreach (
var
c in s_AllNullableFlowStates)
127020
var
leftFirst = a.Join(b).Join(c);
127021
var
rightFirst = a.Join(b.Join(c));
127048
foreach (
var
a in s_AllNullableFlowStates)
127050
foreach (
var
b in s_AllNullableFlowStates)
127052
foreach (
var
c in s_AllNullableFlowStates)
127054
var
leftFirst = a.Meet(b).Meet(c);
127055
var
rightFirst = a.Meet(b.Meet(c));
127101
foreach (
var
a in s_AllNullableFlowStates)
127103
foreach (
var
b in s_AllNullableFlowStates)
127105
var
leftFirst = a.Join(b);
127106
var
rightFirst = b.Join(a);
127129
foreach (
var
a in s_AllNullableFlowStates)
127131
foreach (
var
b in s_AllNullableFlowStates)
127133
var
leftFirst = a.Meet(b);
127134
var
rightFirst = b.Meet(a);