Report nullable ctor warnings for struct primary constructors (#74844)

Author: RikkiGibson

src/Compilers/CSharp/Portable/Binder/Binder_Statements.cs

@@ -3581,7 +3581,7 @@ private BoundNode BindSimpleProgramCompilationUnit(CompilationUnitSyntax compila
         private BoundNode BindPrimaryConstructorBody(TypeDeclarationSyntax typeDecl, BindingDiagnosticBag diagnostics)
         {
             Debug.Assert(typeDecl.ParameterList is object);
-            Debug.Assert(typeDecl.Kind() is SyntaxKind.RecordDeclaration or SyntaxKind.ClassDeclaration);
+            Debug.Assert(typeDecl.Kind() is SyntaxKind.RecordDeclaration or SyntaxKind.ClassDeclaration or SyntaxKind.RecordStructDeclaration or SyntaxKind.StructDeclaration);
 
             BoundExpressionStatement initializer;
             ImmutableArray<LocalSymbol> constructorLocals;

src/Compilers/CSharp/Portable/Compiler/MethodCompiler.cs

@@ -1735,12 +1735,7 @@ private static void GetStateMachineSlotDebugInfo(
 
             initializersBody ??= GetSynthesizedEmptyBody(method);
 
-            if (method is SynthesizedPrimaryConstructor primaryCtor && method.ContainingType.IsStructType())
-            {
-                body = BoundBlock.SynthesizedNoLocals(primaryCtor.GetSyntax());
-                nullableInitialState = getInitializerState(body);
-            }
-            else if (method is SourceMemberMethodSymbol sourceMethod)
+            if (method is SourceMemberMethodSymbol sourceMethod)
             {
                 CSharpSyntaxNode syntaxNode = sourceMethod.SyntaxNode;
 

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

@@ -639,8 +639,7 @@ void enforceMemberNotNull(SyntaxNode? syntaxOpt, LocalState state)
                             Debug.Assert(thisParameter is object);
                             thisSlot = GetOrCreateSlot(thisParameter);
                         }
-                        // https://github.com/dotnet/roslyn/issues/46718: give diagnostics on return points, not constructor signature
-                        var exitLocation = method.DeclaringSyntaxReferences.IsEmpty ? null : method.TryGetFirstLocation();
+                        var exitLocation = method is SynthesizedPrimaryConstructor || method.DeclaringSyntaxReferences.IsEmpty ? null : method.TryGetFirstLocation();
                         bool constructorEnforcesRequiredMembers = method.ShouldCheckRequiredMembers();
 
                         // Required properties can be attributed MemberNotNull, indicating that if the property is set, the field will be set as well.

src/Compilers/CSharp/Test/Emit2/Semantics/PrimaryConstructorTests.cs

@@ -22122,5 +22122,95 @@ public event EventHandler OnClosed
             var comp = CreateCompilation(source, options: TestOptions.ReleaseDll);
             comp.VerifyEmitDiagnostics();
         }
+
+        [Theory]
+        [InlineData("class")]
+        [InlineData("struct")]
+        [WorkItem("https://github.com/dotnet/roslyn/issues/74726")]
+        public void PrimaryCtorNullableFieldWarning(string typeKind)
+        {
+            var source = $$"""
+                #nullable enable
+
+                public {{typeKind}} C()
+                {
+                    public string Text { get; set; } // 1
+                    public C(bool ignored) : this() { }
+                }
+
+                public {{typeKind}} C2
+                {
+                    public string Text { get; set; }
+                    public C2() { } // 2
+                }
+
+                public {{typeKind}} C3()
+                {
+                    public string Text { get; set; } = "a";
+                    public C3(bool ignored) : this() { }
+                }
+
+                public {{typeKind}} C4
+                {
+                    public string Text { get; set; }
+                    public C4() { Text = "a"; }
+                }
+                """;
+
+            var comp = CreateCompilation(source);
+            comp.VerifyEmitDiagnostics(
+                // (5,19): warning CS8618: Non-nullable property 'Text' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.
+                //     public string Text { get; set; } // 1
+                Diagnostic(ErrorCode.WRN_UninitializedNonNullableField, "Text").WithArguments("property", "Text").WithLocation(5, 19),
+                // (12,12): warning CS8618: Non-nullable property 'Text' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.
+                //     public C2() { } // 2
+                Diagnostic(ErrorCode.WRN_UninitializedNonNullableField, "C2").WithArguments("property", "Text").WithLocation(12, 12)
+                );
+        }
+
+        [Theory]
+        [InlineData("class")]
+        [InlineData("struct")]
+        [WorkItem("https://github.com/dotnet/roslyn/issues/74726")]
+        public void RecordPrimaryCtorNullableFieldWarning(string typeKind)
+        {
+            var source = $$"""
+                #nullable enable
+
+                public record {{typeKind}} C()
+                {
+                    public string Text { get; set; } // 1
+                    public C(bool ignored) : this() { }
+                }
+
+                public record {{typeKind}} C2
+                {
+                    public string Text { get; set; }
+                    public C2() { } // 2
+                }
+
+                public record {{typeKind}} C3()
+                {
+                    public string Text { get; set; } = "a";
+                    public C3(bool ignored) : this() { }
+                }
+
+                public record {{typeKind}} C4
+                {
+                    public string Text { get; set; }
+                    public C4() { Text = "a"; }
+                }
+                """;
+
+            var comp = CreateCompilation(source);
+            comp.VerifyEmitDiagnostics(
+                // (5,19): warning CS8618: Non-nullable property 'Text' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.
+                //     public string Text { get; set; } // 1
+                Diagnostic(ErrorCode.WRN_UninitializedNonNullableField, "Text").WithArguments("property", "Text").WithLocation(5, 19),
+                // (12,12): warning CS8618: Non-nullable property 'Text' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.
+                //     public C2() { } // 2
+                Diagnostic(ErrorCode.WRN_UninitializedNonNullableField, "C2").WithArguments("property", "Text").WithLocation(12, 12)
+                );
+        }
     }
 }