Merge remote-tracking branch 'upstream/master' into testCleanup

src/Compilers/CSharp/Portable/Binder/Semantics/OverloadResolution/OverloadResolution.cs

@@ -1782,8 +1782,8 @@ private static BetterResult MoreSpecificType(TypeSymbol t1, TypeSymbol t2, ref H
             //   argument is more specific and no type argument is less specific than the
             //   corresponding type argument in the other. 
 
-            var n1 = t1 as NamedTypeSymbol;
-            var n2 = t2 as NamedTypeSymbol;
+            var n1 = t1.TupleUnderlyingTypeOrSelf() as NamedTypeSymbol;
+            var n2 = t2.TupleUnderlyingTypeOrSelf() as NamedTypeSymbol;
             Debug.Assert(((object)n1 == null) == ((object)n2 == null));
 
             if ((object)n1 == null)

src/Compilers/CSharp/Test/Emit/CodeGen/CodeGenTupleTest.cs

@@ -23412,5 +23412,148 @@ void M()
             Assert.Equal("(System.Int32, System.String, System.Int32)", model.GetTypeInfo(tuple).ConvertedType.ToTestDisplayString());
             Assert.Equal(ConversionKind.NoConversion, model.GetConversion(tuple).Kind);
         }
+
+        [Fact]
+        [WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")]
+        public void MoreGenericTieBreaker_01()
+        {
+            var source =
+@"using System;
+public class C
+{
+    public static void Main()
+    {
+        A<A<int>> a = null;
+        M1(a); // ok, selects M1<T>(A<A<T>> a)
+
+        var b = default(ValueTuple<ValueTuple<int, int>, int>);
+        M2(b); // ok, should select M2<T>(ValueTuple<ValueTuple<T, int>, int> a)
+    }
+    public static void M1<T>(A<T> a) { Console.Write(1); }
+    public static void M1<T>(A<A<T>> a) { Console.Write(2); }
+
+    public static void M2<T>(ValueTuple<T, int> a) { Console.Write(3); }
+    public static void M2<T>(ValueTuple<ValueTuple<T, int>, int> a) { Console.Write(4); }
+}
+
+public class A<T> {}";
+            var comp = CompileAndVerify(source, additionalRefs: s_valueTupleRefs, expectedOutput: "24");
+        }
+
+        [Fact]
+        [WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")]
+        public void MoreGenericTieBreaker_01b()
+        {
+            var source =
+@"using System;
+public class C
+{
+    public static void Main()
+    {
+        var b = ((0, 0), 0);
+        M2(b); // ok, should select M2<T>(((T, int), int) a)
+    }
+    public static void M2<T>((T, int) a) { Console.Write(3); }
+    public static void M2<T>(((T, int), int) a) { Console.Write(4); }
+}";
+            var comp = CompileAndVerify(source, additionalRefs: s_valueTupleRefs, expectedOutput: "4");
+        }
+
+        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/20583")]
+        [WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")]
+        [WorkItem(20583, "https://github.com/dotnet/roslyn/issues/20583")]
+        public void MoreGenericTieBreaker_02()
+        {
+            var source =
+@"using System;
+public class C
+{
+    public static void Main()
+    {
+        // var b = (1, 2, 3, 4, 5, 6, 7, 8);
+        var b = new ValueTuple<int, int, int, int, int, int, int, ValueTuple<int>>(1, 2, 3, 4, 5, 6, 7, new ValueTuple<int>(8));
+        M1(b);
+        M2(b); // ok, should select M2<T1, T2, T3, T4, T5, T6, T7, T8>(ValueTuple<T1, T2, T3, T4, T5, T6, T7, ValueTuple<T8>> a)
+    }
+    public static void M1<T1, T2, T3, T4, T5, T6, T7, TRest>(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> a) where TRest : struct { Console.Write(1); }
+    public static void M2<T1, T2, T3, T4, T5, T6, T7, T8>(ValueTuple<T1, T2, T3, T4, T5, T6, T7, ValueTuple<T8>> a) { Console.Write(2); }
+    public static void M2<T1, T2, T3, T4, T5, T6, T7, TRest>(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> a) where TRest : struct { Console.Write(3); }
+}
+";
+            var comp = CompileAndVerify(source,
+                additionalRefs: s_valueTupleRefs,
+                expectedOutput: @"12");
+        }
+
+        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/20583")]
+        [WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")]
+        [WorkItem(20583, "https://github.com/dotnet/roslyn/issues/20583")]
+        public void MoreGenericTieBreaker_02b()
+        {
+            var source =
+@"using System;
+public class C
+{
+    public static void Main()
+    {
+        var b = (1, 2, 3, 4, 5, 6, 7, 8);
+        M1(b);
+        M2(b); // ok, should select M2<T1, T2, T3, T4, T5, T6, T7, T8>((T1, T2, T3, T4, T5, T6, T7, T8) a)
+    }
+    public static void M1<T1, T2, T3, T4, T5, T6, T7, TRest>(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> a) where TRest : struct { Console.Write(1); }
+    public static void M2<T1, T2, T3, T4, T5, T6, T7, T8>((T1, T2, T3, T4, T5, T6, T7, T8) a) { Console.Write(2); }
+    public static void M2<T1, T2, T3, T4, T5, T6, T7, TRest>(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> a) where TRest : struct { Console.Write(3); }
+}
+";
+            var comp = CompileAndVerify(source,
+                additionalRefs: s_valueTupleRefs,
+                expectedOutput: @"12");
+        }
+
+        [Fact]
+        [WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")]
+        public void MoreGenericTieBreaker_03()
+        {
+            var source =
+@"using System;
+public class C
+{
+    public static void Main()
+    {
+        var b = ((1, 1), 2, 3, 4, 5, 6, 7, 8, 9, (10, 10), (11, 11));
+        M1(b); // ok, should select M2<T, U, V>(((T, int), int, int, int, int, int, int, int, int, (U, int), V) a)
+    }
+    public static void M1<T, U, V>(((T, int), int, int, int, int, int, int, int, int, (U, int), V) a)
+        { Console.Write(3); }
+    public static void M1<T, U, V>((T, int, int, int, int, int, int, int, int, U, (V, int)) a)
+        { Console.Write(4); }
+}";
+            var comp = CompileAndVerify(source, additionalRefs: s_valueTupleRefs, expectedOutput: "3");
+        }
+
+        [Fact]
+        [WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")]
+        public void MoreGenericTieBreaker_04()
+        {
+            var source =
+@"using System;
+public class C
+{
+    public static void Main()
+    {
+        var b = ((1, 1), 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, (20, 20));
+        M1(b); // error: ambiguous
+    }
+    public static void M1<T, U>((T, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, (U, int)) a)
+        { Console.Write(3); }
+    public static void M1<T, U>(((T, int), int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, U) a)
+        { Console.Write(4); }
+}";
+            CreateStandardCompilation(source, references: s_valueTupleRefs).VerifyDiagnostics(
+                // (7,9): error CS0121: The call is ambiguous between the following methods or properties: 'C.M1<T, U>((T, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, (U, int)))' and 'C.M1<T, U>(((T, int), int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, U))'
+                //         M1(b); // error: ambiguous
+                Diagnostic(ErrorCode.ERR_AmbigCall, "M1").WithArguments("C.M1<T, U>((T, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, (U, int)))", "C.M1<T, U>(((T, int), int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, int, U))").WithLocation(7, 9)
+                );
+        }
     }
 }

src/Compilers/VisualBasic/Portable/Semantics/OverloadResolution.vb

@@ -4532,8 +4532,8 @@ ContinueCandidatesLoop:
 
             ' Both are generics
             If leftType.Kind = SymbolKind.NamedType AndAlso rightType.Kind = SymbolKind.NamedType Then
-                Dim leftNamedType = DirectCast(leftType, NamedTypeSymbol)
-                Dim rightNamedType = DirectCast(rightType, NamedTypeSymbol)
+                Dim leftNamedType = DirectCast(leftType.GetTupleUnderlyingTypeOrSelf(), NamedTypeSymbol)
+                Dim rightNamedType = DirectCast(rightType.GetTupleUnderlyingTypeOrSelf(), NamedTypeSymbol)
 
                 ' If their arities are equal
                 If leftNamedType.Arity = rightNamedType.Arity Then

src/Compilers/VisualBasic/Test/Emit/CodeGen/CodeGenTuples.vb

@@ -20396,6 +20396,134 @@ BC30311: Value of type '(e As Integer?, String)' cannot be converted to '(Intege
             Assert.Equal(ConversionKind.DelegateRelaxationLevelNone, model.GetConversion(node).Kind)
         End Sub
 
+        <Fact>
+        <WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")>
+        Public Sub MoreGenericTieBreaker_01()
+            Dim verifier = CompileAndVerify(
+<compilation>
+    <file name="a.vb">
+Option Strict On
+
+Imports System
+Module Module1
+    Public Sub Main()
+        Dim a As A(Of A(Of Integer)) = Nothing
+        M1(a) ' ok, selects M1(Of T)(A(Of A(Of T)) a)
+
+        Dim b = New ValueTuple(Of ValueTuple(Of Integer, Integer), Integer)()
+        M2(b) ' ok, should select M2(Of T)(ValueTuple(Of ValueTuple(Of T, Integer), Integer) a)
+    End Sub
+
+    Public Sub M1(Of T)(a As A(Of T))
+        Console.Write(1)
+    End Sub
+    Public Sub M1(Of T)(a As A(Of A(Of T)))
+        Console.Write(2)
+    End Sub
+
+    Public Sub M2(Of T)(a As ValueTuple(Of T, Integer))
+        Console.Write(3)
+    End Sub
+    Public Sub M2(Of T)(a As ValueTuple(Of ValueTuple(Of T, Integer), Integer))
+        Console.Write(4)
+    End Sub
+End Module
+
+Public Class A(Of T)
+End Class
+    </file>
+</compilation>, additionalRefs:=s_valueTupleRefs, expectedOutput:=<![CDATA[
+24
+]]>)
+        End Sub
+
+        <Fact>
+        <WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")>
+        Public Sub MoreGenericTieBreaker_01b()
+            Dim verifier = CompileAndVerify(
+<compilation>
+    <file name="a.vb">
+Option Strict On
+
+Imports System
+Module Module1
+    Public Sub Main()
+        Dim b = ((0, 0), 0)
+        M2(b) ' ok, should select M2(Of T)(ValueTuple(Of ValueTuple(Of T, Integer), Integer) a)
+    End Sub
+
+    Public Sub M2(Of T)(a As (T, Integer))
+        Console.Write(3)
+    End Sub
+    Public Sub M2(Of T)(a As ((T, Integer), Integer))
+        Console.Write(4)
+    End Sub
+End Module
+    </file>
+</compilation>, additionalRefs:=s_valueTupleRefs, expectedOutput:=<![CDATA[
+4
+]]>)
+        End Sub
+
+        <Fact>
+        <WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")>
+        Public Sub MoreGenericTieBreaker_03()
+            Dim verifier = CompileAndVerify(
+<compilation>
+    <file name="a.vb">
+Option Strict On
+
+Imports System
+Module Module1
+    Public Sub Main()
+        Dim b = ((1, 1), 2, 3, 4, 5, 6, 7, 8, 9, (10, 10), (11, 11))
+        M1(b) ' ok, should select M1(Of T, U, V)(a As ((T, Integer), Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, (U, Integer), V))
+    End Sub
+
+    Sub M1(Of T, U, V)(a As ((T, Integer), Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, (U, Integer), V))
+        Console.Write(3)
+    End Sub
+    Sub M1(Of T, U, V)(a As (T, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, U, (V, Integer)))
+        Console.Write(4)
+    End Sub
+End Module
+    </file>
+</compilation>, additionalRefs:=s_valueTupleRefs, expectedOutput:=<![CDATA[
+3
+]]>)
+        End Sub
+
+        <Fact>
+        <WorkItem(20494, "https://github.com/dotnet/roslyn/issues/20494")>
+        Public Sub MoreGenericTieBreaker_04()
+            Dim source =
+<compilation>
+    <file name="a.vb">
+Option Strict On
+
+Imports System
+Module Module1
+    Public Sub Main()
+        Dim b = ((1, 1), 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, (20, 20))
+        M1(b) ' error: ambiguous
+    End Sub
+
+    Sub M1(Of T, U)(a As (T, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, (U, Integer)))
+        Console.Write(3)
+    End Sub
+    Sub M1(Of T, U)(a As ((T, Integer), Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, U))
+        Console.Write(4)
+    End Sub
+End Module
+    </file>
+</compilation>
+            Dim comp = CompilationUtils.CreateCompilationWithMscorlibAndVBRuntimeAndReferences(source, additionalRefs:=s_valueTupleRefs)
+            comp.VerifyDiagnostics(
+    Diagnostic(ERRID.ERR_NoMostSpecificOverload2, "M1").WithArguments("M1", "
+    'Public Sub M1(Of (Integer, Integer), Integer)(a As ((Integer, Integer), Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, (Integer, Integer)))': Not most specific.
+    'Public Sub M1(Of Integer, (Integer, Integer))(a As ((Integer, Integer), Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, Integer, (Integer, Integer)))': Not most specific.").WithLocation(7, 9)
+                )
+        End Sub
     End Class
 
 End Namespace