Use-site diagnostics for a type should include information for type arguments...

Use-site diagnostics for a type should include information for type arguments of contaning types. (#45663)

Fixes #45625.

src/Compilers/CSharp/Portable/Symbols/NamedTypeSymbol.cs

@@ -1223,13 +1223,21 @@ internal override DiagnosticInfo GetUseSiteDiagnostic()
 
         private bool DeriveUseSiteDiagnosticFromTypeArguments(ref DiagnosticInfo result)
         {
-            foreach (TypeWithAnnotations arg in this.TypeArgumentsWithAnnotationsNoUseSiteDiagnostics)
+            NamedTypeSymbol currentType = this;
+
+            do
             {
-                if (DeriveUseSiteDiagnosticFromType(ref result, arg, AllowedRequiredModifierType.None))
+                foreach (TypeWithAnnotations arg in currentType.TypeArgumentsWithAnnotationsNoUseSiteDiagnostics)
                 {
-                    return true;
+                    if (DeriveUseSiteDiagnosticFromType(ref result, arg, AllowedRequiredModifierType.None))
+                    {
+                        return true;
+                    }
                 }
+
+                currentType = currentType.ContainingType;
             }
+            while (currentType?.IsDefinition == false);
 
             return false;
         }

src/Compilers/CSharp/Test/Symbol/Symbols/EnumTests.cs

@@ -311,11 +311,11 @@ private static string GenerateEnum(int n, Func<int, int, string> getMemberValue)
 
         [WorkItem(45625, "https://github.com/dotnet/roslyn/issues/45625")]
         [Fact]
-        public void UseSiteError()
+        public void UseSiteError_01()
         {
             var sourceA =
 @"public class A { }";
-            var comp = CreateCompilation(sourceA);
+            var comp = CreateCompilation(sourceA, assemblyName: "UseSiteError_sourceA");
             var refA = comp.EmitToImageReference();
 
             var sourceB =
@@ -340,17 +340,62 @@ static void Main()
     }
 }";
             comp = CreateCompilation(sourceC, references: new[] { refB });
-            // https://github.com/dotnet/roslyn/issues/45625: A use-site error should be reported for C.F.
-            comp.VerifyDiagnostics();
-            CompileAndVerify(comp);
+            comp.VerifyDiagnostics(
+                // (5,31): error CS0012: The type 'A' is defined in an assembly that is not referenced. You must add a reference to assembly 'UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'.
+                //         const int x = (int)~C.F;
+                Diagnostic(ErrorCode.ERR_NoTypeDef, "F").WithArguments("A", "UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null").WithLocation(5, 31)
+                );
 
             var tree = comp.SyntaxTrees[0];
             var model = comp.GetSemanticModel(tree);
             var expr = tree.GetRoot().DescendantNodes().Single(n => n.Kind() == SyntaxKind.BitwiseNotExpression);
             var value = model.GetConstantValue(expr);
-            // https://github.com/dotnet/roslyn/issues/45625: Binder.FoldUnaryOperator() should return null if C.F has a use-site error.
-            Assert.True(value.HasValue);
-            Assert.Equal(-1, value.Value);
+            Assert.False(value.HasValue);
+        }
+
+        [WorkItem(45625, "https://github.com/dotnet/roslyn/issues/45625")]
+        [Fact]
+        public void UseSiteError_02()
+        {
+            var sourceA =
+@"public class A { }";
+            var comp = CreateCompilation(sourceA, assemblyName: "UseSiteError_sourceA");
+            var refA = comp.EmitToImageReference();
+
+            var sourceB =
+@"public class B<T>
+{
+    public enum E { F }
+}
+public class C
+{
+    public const B<A>.E F = default;
+}";
+            comp = CreateCompilation(sourceB, references: new[] { refA });
+            var refB = comp.EmitToImageReference();
+
+            var sourceC =
+@"class Program
+{
+    static void Main()
+    {
+        var x = ~C.F;
+        System.Console.WriteLine(x);
+    }
+}";
+            comp = CreateCompilation(sourceC, references: new[] { refB }, options: TestOptions.ReleaseExe);
+            comp.VerifyDiagnostics(
+                // (5,20): error CS0012: The type 'A' is defined in an assembly that is not referenced. You must add a reference to assembly 'UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'.
+                //         var x = ~C.F;
+                Diagnostic(ErrorCode.ERR_NoTypeDef, "F").WithArguments("A", "UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null").WithLocation(5, 20)
+                );
+
+            comp = CreateCompilation(sourceC, references: new[] { refB }, options: TestOptions.DebugExe);
+            comp.VerifyDiagnostics(
+                // (5,20): error CS0012: The type 'A' is defined in an assembly that is not referenced. You must add a reference to assembly 'UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'.
+                //         var x = ~C.F;
+                Diagnostic(ErrorCode.ERR_NoTypeDef, "F").WithArguments("A", "UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null").WithLocation(5, 20)
+                );
         }
     }
 }

src/Compilers/VisualBasic/Portable/Symbols/NamedTypeSymbol.vb

@@ -1007,30 +1007,43 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
 
         Private Function DeriveUseSiteErrorInfoFromTypeArguments() As DiagnosticInfo
             Dim argsErrorInfo As DiagnosticInfo = Nothing
+            Dim currentType As NamedTypeSymbol = Me
 
-            For Each arg As TypeSymbol In Me.TypeArgumentsNoUseSiteDiagnostics
-                Dim errorInfo As DiagnosticInfo = DeriveUseSiteErrorInfoFromType(arg)
+            Do
+                For Each arg As TypeSymbol In currentType.TypeArgumentsNoUseSiteDiagnostics
+                    Dim errorInfo As DiagnosticInfo = DeriveUseSiteErrorInfoFromType(arg)
 
-                If errorInfo IsNot Nothing Then
-                    If errorInfo.Code = ERRID.ERR_UnsupportedType1 Then
-                        Return errorInfo
-                    End If
+                    If errorInfo IsNot Nothing Then
+                        If errorInfo.Code = ERRID.ERR_UnsupportedType1 Then
+                            Return errorInfo
+                        End If
 
-                    If argsErrorInfo Is Nothing Then
-                        argsErrorInfo = errorInfo
+                        If argsErrorInfo Is Nothing Then
+                            argsErrorInfo = errorInfo
+                        End If
                     End If
-                End If
-            Next
+                Next
 
-            If Me.HasTypeArgumentsCustomModifiers Then
-                Dim modifiersErrorInfo As DiagnosticInfo = Nothing
+                If currentType.HasTypeArgumentsCustomModifiers Then
+                    Dim modifiersErrorInfo As DiagnosticInfo = Nothing
 
-                For i As Integer = 0 To Me.Arity - 1
-                    modifiersErrorInfo = MergeUseSiteErrorInfo(modifiersErrorInfo, DeriveUseSiteErrorInfoFromCustomModifiers(Me.GetTypeArgumentCustomModifiers(i)))
-                Next
+                    For i As Integer = 0 To currentType.Arity - 1
+                        modifiersErrorInfo = MergeUseSiteErrorInfo(modifiersErrorInfo, DeriveUseSiteErrorInfoFromCustomModifiers(currentType.GetTypeArgumentCustomModifiers(i)))
+                    Next
 
-                Return MergeUseSiteErrorInfo(argsErrorInfo, modifiersErrorInfo)
-            End If
+                    If modifiersErrorInfo IsNot Nothing Then
+                        If modifiersErrorInfo.Code = ERRID.ERR_UnsupportedType1 Then
+                            Return modifiersErrorInfo
+                        End If
+
+                        If argsErrorInfo Is Nothing Then
+                            argsErrorInfo = modifiersErrorInfo
+                        End If
+                    End If
+                End If
+
+                currentType = currentType.ContainingType
+            Loop While currentType IsNot Nothing AndAlso Not currentType.IsDefinition
 
             Return argsErrorInfo
         End Function

src/Compilers/VisualBasic/Test/Symbol/SymbolsTests/Source/EnumTests.vb

@@ -1404,6 +1404,107 @@ BC30060: Conversion from 'E' to 'Integer' cannot occur in a constant expression.
             Return currentSymbol
         End Function
 
+        <WorkItem(45625, "https://github.com/dotnet/roslyn/issues/45625")>
+        <Fact>
+        Public Sub UseSiteError_01()
+            Dim sourceA =
+"
+public class A
+End Class
+"
+            Dim comp = CreateCompilation(sourceA, assemblyName:="UseSiteError_sourceA")
+            Dim refA = comp.EmitToImageReference()
+
+            Dim sourceB =
+"
+public class B( Of T)
+    public enum E
+        F
+    end enum
+end class
+public class C
+    public const F as B(Of A).E = Nothing
+end class
+"
+            comp = CreateCompilation(sourceB, references:={refA})
+            Dim refB = comp.EmitToImageReference()
+
+            Dim sourceC =
+"
+class Program
+    Shared Sub Main()
+        const x As Integer = CType(Not C.F, Integer)
+        System.Console.WriteLine(x)
+    End Sub
+end class
+"
+            comp = CreateCompilation(sourceC, references:={refB})
+            comp.AssertTheseDiagnostics(
+<expected>
+BC30652: Reference required to assembly 'UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' containing the type 'A'. Add one to your project.
+        const x As Integer = CType(Not C.F, Integer)
+                                       ~~~
+</expected>)
+
+            Dim tree = comp.SyntaxTrees(0)
+            Dim model = comp.GetSemanticModel(tree)
+            Dim expr = tree.GetRoot().DescendantNodes().Single(Function(n) n.Kind() = SyntaxKind.NotExpression)
+            Dim value = model.GetConstantValue(expr)
+            Assert.True(value.HasValue)
+            Assert.Equal(-1, value.Value)
+        End Sub
+
+        <WorkItem(45625, "https://github.com/dotnet/roslyn/issues/45625")>
+        <Fact>
+        Public Sub UseSiteError_02()
+            Dim sourceA =
+"
+public class A
+End Class
+"
+            Dim comp = CreateCompilation(sourceA, assemblyName:="UseSiteError_sourceA")
+            Dim refA = comp.EmitToImageReference()
+
+            Dim sourceB =
+"
+public class B( Of T)
+    public enum E
+        F
+    end enum
+end class
+public class C
+    public const F as B(Of A).E = Nothing
+end class
+"
+            comp = CreateCompilation(sourceB, references:={refA})
+            Dim refB = comp.EmitToImageReference()
+
+            Dim sourceC =
+"
+Option Infer On 
+class Program
+    Shared Sub Main()
+        Dim x = Not C.F
+        System.Console.WriteLine(x)
+    End Sub
+end class
+"
+            comp = CreateCompilation(sourceC, references:={refB}, options:=TestOptions.ReleaseExe)
+            comp.AssertTheseDiagnostics(
+<expected>
+BC30652: Reference required to assembly 'UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' containing the type 'A'. Add one to your project.
+        Dim x = Not C.F
+                    ~~~
+</expected>)
+
+            comp = CreateCompilation(sourceC, references:={refB}, options:=TestOptions.DebugExe)
+            comp.AssertTheseDiagnostics(
+<expected>
+BC30652: Reference required to assembly 'UseSiteError_sourceA, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' containing the type 'A'. Add one to your project.
+        Dim x = Not C.F
+                    ~~~
+</expected>)
+        End Sub
     End Class
 
 End Namespace