Misc.

src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs

@@ -1596,6 +1596,14 @@ private static BoundExpression SkipReferenceConversions(BoundExpression possibly
             return possiblyConversion;
         }
 
+        // https://github.com/dotnet/roslyn/issues/30140: Track nullable state from ??=.
+        public override BoundNode VisitNullCoalescingAssignmentOperator(BoundNullCoalescingAssignmentOperator node)
+        {
+            var result = base.VisitNullCoalescingAssignmentOperator(node);
+            SetResult(node);
+            return result;
+        }
+
         public override BoundNode VisitNullCoalescingOperator(BoundNullCoalescingOperator node)
         {
             Debug.Assert(!IsConditionalState);

src/Compilers/CSharp/Portable/LanguageVersion.cs

@@ -332,9 +332,9 @@ public static LanguageVersion MapSpecifiedToEffectiveVersion(this LanguageVersio
             switch (version)
             {
                 case LanguageVersion.Latest:
-                    return LanguageVersion.CSharp8;
+                    return LanguageVersion.CSharp7_3;
                 case LanguageVersion.Default:
-                    return LanguageVersion.CSharp8;
+                    return LanguageVersion.CSharp7;
                 default:
                     return version;
             }

src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs

@@ -273,6 +273,7 @@ private IOperation CreateInternal(BoundNode boundNode)
                 case BoundKind.RefValueOperator:
                 case BoundKind.Sequence:
                 case BoundKind.StackAllocArrayCreation:
+                case BoundKind.SuppressNullableWarningExpression:
                 case BoundKind.TypeExpression:
                 case BoundKind.TypeOrValueExpression:
 

src/Compilers/CSharp/Portable/Symbols/Synthesized/InjectedNonNullTypesAttributeSymbol.cs

@@ -36,7 +36,7 @@ ImmutableArray<MethodSymbol> makeConstructor(CSharpCompilation compilation, Name
                 Binder.ReportUseSiteDiagnostics(boolType, diagnostics, Location.None);
 
                 var boolWithAnnotations = TypeSymbolWithAnnotations.Create(boolType);
-                // PROTOTYPE constructor should save the parameter into a field (for users of reflection)
+                // PROTOTYPE(NullableReferenceTypes): Constructor should save the parameter into a field (for users of reflection)
                 return ImmutableArray.Create<MethodSymbol>(
                     new NonNullTypesAttributeConstructorSymbol(
                         containingType,

src/Compilers/CSharp/Test/Semantic/Semantics/NullableReferenceTypesTests.cs

@@ -1000,8 +1000,8 @@ namespace NotMicrosoft.CodeAnalysis { }
                 ((NamespaceSymbol)comp.SourceModule.GlobalNamespace.GetMember("Microsoft.CodeAnalysis")).GetMembers().Single().ToTestDisplayString());
         }
 
-        // PROTOTYPE Test emitting netmodule (we'll won't inject NNT)
-        // PROTOTYPE test script
+        // PROTOTYPE(NullableReferenceTypes): Test emitting netmodule (we won't inject NNT)
+        // PROTOTYPE(NullableReferenceTypes): Test script
 
         [Theory]
         [InlineData(NonNullTypesTrue)]
@@ -7359,7 +7359,7 @@ partial class C1
     { }
 }";
             var compilation = CreateCompilation(new[] { source, NonNullTypesTrue });
-            // PROTOTYPE(NullReferenceTypes): What nullability is getting emitted?
+            // PROTOTYPE(NullableReferenceTypes): What nullability is getting emitted?
             compilation.VerifyDiagnostics(
                  // (16,18): warning CS8611: Nullability of reference types in type of parameter 'x' doesn't match partial method declaration.
                  //     partial void M1<T>(T? x, T[]? y, System.Action<T?> z, System.Action<T?[]?>?[]? u) where T : class
@@ -7492,7 +7492,7 @@ partial class C1
     { }
 }";
             var compilation = CreateCompilation(new[] { source });
-            // PROTOTYPE(NullReferenceTypes): Missing WRN_MissingNonNullTypesContextForAnnotation for '?' in 
+            // PROTOTYPE(NullableReferenceTypes): Missing WRN_MissingNonNullTypesContextForAnnotation for '?' in 
             // (17,18): 
             //     partial void M1<T>(T? x, T[]? y, System.Action<T?> z, System.Action<T?[]?>?[]? u) where T : class
             compilation.VerifyDiagnostics(
@@ -8187,7 +8187,7 @@ class CL1
 {
 }
 ", NonNullTypesTrue });
-            // PROTOTYPE(NullReferenceTypes): Should report WRN_NullReferenceAssignment for `ref x3`
+            // PROTOTYPE(NullableReferenceTypes): Should report WRN_NullReferenceAssignment for `ref x3`
             // even though the local is unassigned. (The local should be treated as an l-value for assignment.)
             c.VerifyDiagnostics(
                 // (12,12): warning CS8604: Possible null reference argument for parameter 'p' in 'void C.M1(CL1 p)'.
@@ -25276,7 +25276,7 @@ class CL1
     }
 }
 ", NonNullTypesTrue });
-            // PROTOTYPE(NullReferenceTypes): Should report WRN_NullReferenceAssignment for `x7--`
+            // PROTOTYPE(NullableReferenceTypes): Should report WRN_NullReferenceAssignment for `x7--`
             // even though the local is unassigned. (The local should be treated as an l-value for assignment.)
             c.VerifyDiagnostics(
                 // (10,21): warning CS8604: Possible null reference argument for parameter 'x' in 'CL0 CL0.operator ++(CL0 x)'.

src/Compilers/CSharp/Test/Symbol/DeclarationTests.cs

@@ -288,7 +288,7 @@ public class B
 
             var countedTree = new CountedSyntaxTree(foreignType);
 
-            var compilation = CreateCompilation(new SyntaxTree[] { underlyingTree, countedTree });
+            var compilation = CreateCompilation(new SyntaxTree[] { underlyingTree, countedTree }, skipUsesIsNullable: true);
 
             var type = compilation.Assembly.GlobalNamespace.GetTypeMembers().First();
             Assert.Equal(1, countedTree.AccessCount);   // parse once to build the decl table

src/Compilers/Core/Portable/Operations/OperationKind.cs

@@ -192,7 +192,6 @@ public enum OperationKind
         ConstructorBodyOperation = 0x59,
         /// <summary>Indicates an <see cref="IDiscardOperation"/>.</summary>
         Discard = 0x5A,
-
         /// <summary>Indicates an <see cref="IFlowCaptureOperation"/>.</summary>
         FlowCapture = 0x5B,
         /// <summary>Indicates an <see cref="IFlowCaptureReferenceOperation"/>.</summary>
@@ -205,11 +204,10 @@ public enum OperationKind
         StaticLocalInitializationSemaphore = 0x5F,
         /// <summary>Indicates an <see cref="IFlowAnonymousFunctionOperation"/>.</summary>
         FlowAnonymousFunction = 0x60,
-        /// <summary>Indicates an <see cref="ISuppressNullableWarningOperation"/>.</summary>
-        SuppressNullableWarning = 0x61,
-
         /// <summary>Indicates an <see cref="ICoalesceAssignmentOperation"/>.</summary>
         CoalesceAssignment = 0x61,
+        /// <summary>Indicates an <see cref="ISuppressNullableWarningOperation"/>.</summary>
+        SuppressNullableWarning = 0x62,
 
         // /// <summary>Indicates an <see cref="IFixedOperation"/>.</summary>
         // https://github.com/dotnet/roslyn/issues/21281

src/Compilers/Core/Portable/PublicAPI.Unshipped.txt

@@ -29,7 +29,7 @@ Microsoft.CodeAnalysis.FlowAnalysis.IStaticLocalInitializationSemaphoreOperation
 Microsoft.CodeAnalysis.FlowAnalysis.IStaticLocalInitializationSemaphoreOperation.Local.get -> Microsoft.CodeAnalysis.ILocalSymbol
 Microsoft.CodeAnalysis.IOperation.SemanticModel.get -> Microsoft.CodeAnalysis.SemanticModel
 Microsoft.CodeAnalysis.OperationKind.CoalesceAssignment = 97 -> Microsoft.CodeAnalysis.OperationKind
-Microsoft.CodeAnalysis.OperationKind.SuppressNullableWarning = 97 -> Microsoft.CodeAnalysis.OperationKind
+Microsoft.CodeAnalysis.OperationKind.SuppressNullableWarning = 98 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.Operations.CommonConversion.IsImplicit.get -> bool
 Microsoft.CodeAnalysis.Operations.ICoalesceAssignmentOperation
 Microsoft.CodeAnalysis.Operations.ISuppressNullableWarningOperation

src/EditorFeatures/CSharpTest/Diagnostics/GenerateType/GenerateTypeTests.cs

@@ -1536,7 +1536,7 @@ internal class T
 {
     public T(out DateTime d)
     {
-        d = default;
+        d = default(DateTime);
     }
 }",
 index: 1);
@@ -1684,7 +1684,7 @@ private class T
     {
         public T(out X d)
         {
-            d = default;
+            d = default(X);
         }
     }
 }",

src/EditorFeatures/CSharpTest/Diagnostics/UpgradeProject/UpgradeProjectTests.cs

@@ -550,7 +550,8 @@ void A()
     </Project>
 </Workspace>",
                 new[] {
-                    string.Format(CSharpFeaturesResources.Upgrade_this_project_to_csharp_language_version_0, "7.0")
+                    string.Format(CSharpFeaturesResources.Upgrade_this_project_to_csharp_language_version_0, "7.0"),
+                    string.Format(CSharpFeaturesResources.Upgrade_all_csharp_projects_to_language_version_0, "7.0")
                     });
         }
 
@@ -584,13 +585,16 @@ public async Task OnlyOfferFixAllProjectsToDefaultWhenApplicable()
             string defaultEffectiveVersion = LanguageVersion.Default.MapSpecifiedToEffectiveVersion().ToDisplayString();
             await TestExactActionSetOfferedAsync(
 
-@"<Workspace>
+$@"<Workspace>
     <Project Language=""C#"" LanguageVersion=""6"">
         <Document>
 class C
-{
-    object F = [|null!|];
-}
+{{
+    void A()
+    {{
+#error version:[|{defaultEffectiveVersion}|]
+    }}
+}}
         </Document>
     </Project>
     <Project Language=""C#"" LanguageVersion=""Default"">

src/EditorFeatures/CSharpTest/GenerateFromMembers/AddConstructorParametersFromMembers/AddConstructorParametersFromMembersTests.cs

@@ -326,7 +326,7 @@ public Program((int, string) i)
     (int, string) i;
     (string, int) s;
 
-    public Program((int, string) i, (string, int) s = default)
+    public Program((int, string) i, (string, int) s = default((string, int)))
     {
         this.i = i;
         this.s = s;
@@ -382,7 +382,7 @@ public Program((int a, string b) i)
     (int a, string b) i;
     (string c, int d) s;
 
-    public Program((int a, string b) i, (string c, int d) s = default)
+    public Program((int a, string b) i, (string c, int d) s = default((string c, int d)))
     {
         this.i = i;
         this.s = s;

src/EditorFeatures/CSharpTest/GenerateVariable/GenerateVariableTests.cs

@@ -3991,7 +3991,7 @@ void bar(sfoo x)
 {
     void goo()
     {
-        sfoo xyz = default;
+        sfoo xyz = default(sfoo);
         bar(xyz);
     }
 

src/EditorFeatures/CSharpTest/ImplementAbstractClass/ImplementAbstractClassTests.cs

@@ -459,7 +459,7 @@ abstract class d
 
 class c : d
 {
-    public override void goo(b x = default)
+    public override void goo(b x = default(b))
     {
         throw new System.NotImplementedException();
     }
@@ -1564,7 +1564,7 @@ abstract class B
 }
 sealed class D : B
 {
-    public override void M1(int i = 0, string s = null, int? j = null, V v = default)
+    public override void M1(int i = 0, string s = null, int? j = null, V v = default(V))
     {
         throw new System.NotImplementedException();
     }

src/EditorFeatures/Test2/IntelliSense/CSharpCompletionCommandHandlerTests.vb

@@ -1949,7 +1949,7 @@ class D : C
                 state.SendTypeChars(" Goo")
                 state.SendTab()
                 Await state.AssertNoCompletionSession()
-                Assert.Contains("public override void Goo<S>(S x = default)", state.SubjectBuffer.CurrentSnapshot.GetText(), StringComparison.Ordinal)
+                Assert.Contains("public override void Goo<S>(S x = default(S))", state.SubjectBuffer.CurrentSnapshot.GetText(), StringComparison.Ordinal)
             End Using
         End Function
 

src/VisualStudio/Core/Test/CodeModel/CSharp/CodeClassTests.vb

@@ -2160,7 +2160,7 @@ class C
 {
     string Name
     {
-        get => default;
+        get => default(string);
         set
         {
         }
@@ -2188,7 +2188,7 @@ class C
     {
         get
         {
-            return default;
+            return default(string);
         }
 
         set
@@ -2220,7 +2220,7 @@ class C$$
 <Code>
 class C
 {
-    string Name => default;
+    string Name => default(string);
 }
 </Code>
 
@@ -2244,7 +2244,7 @@ class C
     {
         get
         {
-            return default;
+            return default(string);
         }
     }
 }

src/Workspaces/MSBuildTest/MSBuildWorkspaceTests.cs

@@ -1765,7 +1765,7 @@ public async Task TestParseOptions_CSharp_Compatibility_None()
         public async Task TestParseOptions_CSharp_LanguageVersion_Default()
         {
             CreateCSharpFiles();
-            await AssertCSParseOptionsAsync(CS.LanguageVersion.CSharp8, options => options.LanguageVersion);
+            await AssertCSParseOptionsAsync(CS.LanguageVersion.CSharp7, options => options.LanguageVersion);
         }
 
         [ConditionalFact(typeof(VisualStudioMSBuildInstalled)), Trait(Traits.Feature, Traits.Features.MSBuildWorkspace)]