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Fix unexpected conditional state in nullable analysis of conditional access #78439

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Merged
merged 3 commits into from
May 8, 2025
Merged

Fix unexpected conditional state in nullable analysis of conditional access #78439

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86446ae
Fix unexpected conditional state in nullable analysis of conditional …
jjonescz May 2, 2025
d62c9d2
Merge branch 'main' into 78386-NullableConditionalAssert
jjonescz May 7, 2025
60ecfa6
Move unsplit
jjonescz May 7, 2025
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1 change: 1 addition & 0 deletions src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -5921,6 +5921,7 @@ private void VisitConditionalAccess(BoundConditionalAccess node, out PossiblyCon
// Therefore we do a VisitPossibleConditionalAccess here which unconditionally includes the "after receiver" state in State
// and includes the "after subsequent conditional accesses" in stateWhenNotNull
VisitPossibleConditionalAccess(node.AccessExpression, out stateWhenNotNull);
Unsplit();
}
else
{
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7 changes: 4 additions & 3 deletions src/Compilers/CSharp/Test/Emit3/FlowAnalysis/FlowTests.cs
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Expand Up @@ -2387,8 +2387,9 @@ void M2(C c1)
Diagnostic(ErrorCode.ERR_UseDefViolation, "x").WithArguments("x").WithLocation(17, 15));
}

[Fact]
public void NullCoalescing_CondAccess_NonNullConstantLeft()
[Theory, CombinatorialData, WorkItem("https://github.com/dotnet/roslyn/issues/78386")]
public void NullCoalescing_CondAccess_NonNullConstantLeft(
[CombinatorialValues(TargetFramework.Standard, TargetFramework.NetCoreApp)] TargetFramework targetFramework)
{
var source = @"
#nullable enable
Expand All @@ -2414,7 +2415,7 @@ static void M2()
}
}
";
CreateCompilation(source).VerifyDiagnostics(
CreateCompilation(source, targetFramework: targetFramework).VerifyDiagnostics(
// (21,30): error CS0165: Use of unassigned local variable 'z'
// : x.ToString() + z.ToString(); // 1
Diagnostic(ErrorCode.ERR_UseDefViolation, "z").WithArguments("z").WithLocation(21, 30)
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48 changes: 45 additions & 3 deletions src/Compilers/CSharp/Test/Semantic/Semantics/NullableReferenceTypesTests.cs
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Expand Up @@ -54206,8 +54206,9 @@ static void M2(E? e, object? x)
}

// <remarks>Ported from <see cref="FlowTests.NullCoalescing_CondAccess_NonNullConstantLeft"/>.</remarks>
[Fact]
public void NullCoalescing_CondAccess_NonNullConstantLeft()
[Theory, CombinatorialData, WorkItem("https://github.com/dotnet/roslyn/issues/78386")]
public void NullCoalescing_CondAccess_NonNullConstantLeft(
[CombinatorialValues(TargetFramework.Standard, TargetFramework.NetCoreApp)] TargetFramework targetFramework)
{
var source = @"
static class C
Expand All @@ -54229,12 +54230,53 @@ static void M2(object? x, object? y)
}
}
";
CreateNullableCompilation(source).VerifyDiagnostics(
CreateCompilation(source, targetFramework: targetFramework, options: WithNullableEnable()).VerifyDiagnostics(
// (17,30): warning CS8602: Dereference of a possibly null reference.
// : x.ToString() + y.ToString(); // 1
Diagnostic(ErrorCode.WRN_NullReferenceReceiver, "y").WithLocation(17, 30));
}

[Fact, WorkItem("https://github.com/dotnet/roslyn/issues/78386")]
public void CondAccess_PostConditionInArgument_01()
{
var source = """
using System.Diagnostics.CodeAnalysis;
static class C
{
static bool M1(this string s, [NotNullWhen(true)] string? x) => true;
static void M2(string? x)
{
_ = ""?.M1(x = "s") ?? false
? x.ToString()
: x.ToString();
}
}
""";
CreateCompilation([source, NotNullWhenAttributeDefinition], options: WithNullableEnable()).VerifyDiagnostics();
}

[Fact, WorkItem("https://github.com/dotnet/roslyn/issues/78386")]
public void CondAccess_PostConditionInArgument_02()
{
var source = """
using System.Diagnostics.CodeAnalysis;
static class C
{
static bool M1(this string s, [NotNullWhen(true)] string? x) => true;
static void M2(string? x)
{
_ = ""?.M1(x) ?? false
? x.ToString()
: x.ToString();
}
}
""";
CreateCompilation([source, NotNullWhenAttributeDefinition], options: WithNullableEnable()).VerifyDiagnostics(
// (9,15): warning CS8602: Dereference of a possibly null reference.
// : x.ToString();
Diagnostic(ErrorCode.WRN_NullReferenceReceiver, "x").WithLocation(9, 15));
}

// <remarks>Ported from <see cref="FlowTests.NullCoalescing_NonNullConstantLeft"/>.</remarks>
[Fact]
public void NullCoalescing_NonNullConstantLeft()
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