Supporting complex types in ENC (#19283)

src/Compilers/CSharp/Portable/Emitter/EditAndContinue/CSharpSymbolMatcher.cs

@@ -498,7 +498,7 @@ public override Symbol VisitNamedType(NamedTypeSymbol sourceType)
                         return null;
                     }
 
-                    return TupleTypeSymbol.Create(otherDef, sourceType.TupleElementNames);
+                    return otherDef;
                 }
 
                 Debug.Assert(sourceType.IsDefinition);
@@ -888,6 +888,12 @@ public override Symbol VisitDynamicType(DynamicTypeSymbol symbol)
 
             public override Symbol VisitNamedType(NamedTypeSymbol type)
             {
+                if (type.IsTupleType)
+                {
+                    type = type.TupleUnderlyingType;
+                    Debug.Assert(!type.IsTupleType);
+                }
+
                 var originalDef = type.OriginalDefinition;
                 if ((object)originalDef != type)
                 {

src/Compilers/CSharp/Test/Emit/Emit/EditAndContinue/LocalSlotMappingTests.cs

@@ -3824,5 +3824,204 @@ .maxstack  2
 }
 ", methodToken: diff1.UpdatedMethods.Single());
         }
+
+        [Fact]
+        public void ComplexTypes()
+        {
+            var sourceText = @"
+using System;
+using System.Collections.Generic;
+
+class C1<T>
+{
+    public enum E
+    {
+        A
+    }
+}
+
+class C
+{
+    public unsafe static void G()
+    {        
+        var <N:0>a</N:0> = new { key = ""a"", value = new List<(int, int)>()};
+        var <N:1>b</N:1> = (number: 5, value: a);
+        var <N:2>c</N:2> = new[] { b };
+        int[] <N:3>array</N:3> = { 1, 2, 3 };
+        ref int <N:4>d</N:4> = ref array[0];
+        C1<(int, dynamic)>.E***[,,] <N:5>x</N:5> = null;
+    }
+}
+";
+            var source0 = MarkedSource(sourceText);
+            var source1 = MarkedSource(sourceText);
+            var source2 = MarkedSource(sourceText);
+
+            var compilation0 = CreateStandardCompilation(source0.Tree, options: ComSafeDebugDll.WithAllowUnsafe(true), references: s_valueTupleRefs);
+            var compilation1 = compilation0.WithSource(source1.Tree);
+            var compilation2 = compilation1.WithSource(source2.Tree);
+
+            var f0 = compilation0.GetMember<MethodSymbol>("C.G");
+            var f1 = compilation1.GetMember<MethodSymbol>("C.G");
+            var f2 = compilation2.GetMember<MethodSymbol>("C.G");
+
+            var v0 = CompileAndVerify(compilation0);
+            v0.VerifyIL("C.G", @"
+{
+  // Code size       72 (0x48)
+  .maxstack  4
+  .locals init (<>f__AnonymousType0<string, System.Collections.Generic.List<(int, int)>> V_0, //a
+                System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>> V_1, //b
+                (int number, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value> value)[] V_2, //c
+                int[] V_3, //array
+                int& V_4, //d
+                C1<(int, dynamic)>.E***[,,] V_5) //x
+  IL_0000:  nop
+  IL_0001:  ldstr      ""a""
+  IL_0006:  newobj     ""System.Collections.Generic.List<(int, int)>..ctor()""
+  IL_000b:  newobj     ""<>f__AnonymousType0<string, System.Collections.Generic.List<(int, int)>>..ctor(string, System.Collections.Generic.List<(int, int)>)""
+  IL_0010:  stloc.0
+  IL_0011:  ldloca.s   V_1
+  IL_0013:  ldc.i4.5
+  IL_0014:  ldloc.0
+  IL_0015:  call       ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>..ctor(int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>)""
+  IL_001a:  ldc.i4.1
+  IL_001b:  newarr     ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>""
+  IL_0020:  dup
+  IL_0021:  ldc.i4.0
+  IL_0022:  ldloc.1
+  IL_0023:  stelem     ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>""
+  IL_0028:  stloc.2
+  IL_0029:  ldc.i4.3
+  IL_002a:  newarr     ""int""
+  IL_002f:  dup
+  IL_0030:  ldtoken    ""<PrivateImplementationDetails>.__StaticArrayInitTypeSize=12 <PrivateImplementationDetails>.E429CCA3F703A39CC5954A6572FEC9086135B34E""
+  IL_0035:  call       ""void System.Runtime.CompilerServices.RuntimeHelpers.InitializeArray(System.Array, System.RuntimeFieldHandle)""
+  IL_003a:  stloc.3
+  IL_003b:  ldloc.3
+  IL_003c:  ldc.i4.0
+  IL_003d:  ldelema    ""int""
+  IL_0042:  stloc.s    V_4
+  IL_0044:  ldnull
+  IL_0045:  stloc.s    V_5
+  IL_0047:  ret
+}
+");
+
+            var md0 = ModuleMetadata.CreateFromImage(v0.EmittedAssemblyData);
+
+            var generation0 = EmitBaseline.CreateInitialBaseline(md0, v0.CreateSymReader().GetEncMethodDebugInfo);
+            var diff1 = compilation1.EmitDifference(
+                generation0,
+                ImmutableArray.Create(
+                    new SemanticEdit(SemanticEditKind.Update, f0, f1, GetSyntaxMapFromMarkers(source0, source1), preserveLocalVariables: true)));
+
+            diff1.VerifyIL("C.G", @"
+{
+  // Code size       73 (0x49)
+  .maxstack  4
+  .locals init (<>f__AnonymousType0<string, System.Collections.Generic.List<(int, int)>> V_0, //a
+                System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>> V_1, //b
+                (int number, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value> value)[] V_2, //c
+                int[] V_3, //array
+                int& V_4, //d
+                C1<(int, dynamic)>.E***[,,] V_5) //x
+  IL_0000:  nop
+  IL_0001:  ldstr      ""a""
+  IL_0006:  newobj     ""System.Collections.Generic.List<(int, int)>..ctor()""
+  IL_000b:  newobj     ""<>f__AnonymousType0<string, System.Collections.Generic.List<(int, int)>>..ctor(string, System.Collections.Generic.List<(int, int)>)""
+  IL_0010:  stloc.0
+  IL_0011:  ldloca.s   V_1
+  IL_0013:  ldc.i4.5
+  IL_0014:  ldloc.0
+  IL_0015:  call       ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>..ctor(int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>)""
+  IL_001a:  ldc.i4.1
+  IL_001b:  newarr     ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>""
+  IL_0020:  dup
+  IL_0021:  ldc.i4.0
+  IL_0022:  ldloc.1
+  IL_0023:  stelem     ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>""
+  IL_0028:  stloc.2
+  IL_0029:  ldc.i4.3
+  IL_002a:  newarr     ""int""
+  IL_002f:  dup
+  IL_0030:  ldc.i4.0
+  IL_0031:  ldc.i4.1
+  IL_0032:  stelem.i4
+  IL_0033:  dup
+  IL_0034:  ldc.i4.1
+  IL_0035:  ldc.i4.2
+  IL_0036:  stelem.i4
+  IL_0037:  dup
+  IL_0038:  ldc.i4.2
+  IL_0039:  ldc.i4.3
+  IL_003a:  stelem.i4
+  IL_003b:  stloc.3
+  IL_003c:  ldloc.3
+  IL_003d:  ldc.i4.0
+  IL_003e:  ldelema    ""int""
+  IL_0043:  stloc.s    V_4
+  IL_0045:  ldnull
+  IL_0046:  stloc.s    V_5
+  IL_0048:  ret
+}
+");
+
+            var diff2 = compilation2.EmitDifference(
+               diff1.NextGeneration,
+               ImmutableArray.Create(
+                   new SemanticEdit(SemanticEditKind.Update, f1, f2, GetSyntaxMapFromMarkers(source1, source2), preserveLocalVariables: true)));
+
+            diff2.VerifyIL("C.G", @"
+{
+  // Code size       73 (0x49)
+  .maxstack  4
+  .locals init (<>f__AnonymousType0<string, System.Collections.Generic.List<(int, int)>> V_0, //a
+                System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>> V_1, //b
+                (int number, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value> value)[] V_2, //c
+                int[] V_3, //array
+                int& V_4, //d
+                C1<(int, dynamic)>.E***[,,] V_5) //x
+  IL_0000:  nop
+  IL_0001:  ldstr      ""a""
+  IL_0006:  newobj     ""System.Collections.Generic.List<(int, int)>..ctor()""
+  IL_000b:  newobj     ""<>f__AnonymousType0<string, System.Collections.Generic.List<(int, int)>>..ctor(string, System.Collections.Generic.List<(int, int)>)""
+  IL_0010:  stloc.0
+  IL_0011:  ldloca.s   V_1
+  IL_0013:  ldc.i4.5
+  IL_0014:  ldloc.0
+  IL_0015:  call       ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>..ctor(int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>)""
+  IL_001a:  ldc.i4.1
+  IL_001b:  newarr     ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>""
+  IL_0020:  dup
+  IL_0021:  ldc.i4.0
+  IL_0022:  ldloc.1
+  IL_0023:  stelem     ""System.ValueTuple<int, <anonymous type: string key, System.Collections.Generic.List<(int, int)> value>>""
+  IL_0028:  stloc.2
+  IL_0029:  ldc.i4.3
+  IL_002a:  newarr     ""int""
+  IL_002f:  dup
+  IL_0030:  ldc.i4.0
+  IL_0031:  ldc.i4.1
+  IL_0032:  stelem.i4
+  IL_0033:  dup
+  IL_0034:  ldc.i4.1
+  IL_0035:  ldc.i4.2
+  IL_0036:  stelem.i4
+  IL_0037:  dup
+  IL_0038:  ldc.i4.2
+  IL_0039:  ldc.i4.3
+  IL_003a:  stelem.i4
+  IL_003b:  stloc.3
+  IL_003c:  ldloc.3
+  IL_003d:  ldc.i4.0
+  IL_003e:  ldelema    ""int""
+  IL_0043:  stloc.s    V_4
+  IL_0045:  ldnull
+  IL_0046:  stloc.s    V_5
+  IL_0048:  ret
+}
+");
+        }
     }
 }
\ No newline at end of file

src/Compilers/CSharp/Test/Emit/Emit/EditAndContinue/SymbolMatcherTests.cs

@@ -769,7 +769,7 @@ public class C
     public delegate (int, int) F();
 }";
             var source1 = @"
-public struct C
+public class C
 {
     public delegate (int, bool) F();
 }";
@@ -799,7 +799,7 @@ public class C
     public delegate (int, int) F();
 }";
             var source1 = @"
-public struct C
+public class C
 {
     public delegate (int x, int y) F();
 }";

src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicSymbolMatcher.vb

@@ -402,7 +402,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Emit
                         Return Nothing
                     End If
 
-                    Return TupleTypeSymbol.Create(otherDef, type.TupleElementNames)
+                    Return otherDef
                 End If
 
                 Debug.Assert(type.IsDefinition)
@@ -652,10 +652,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Emit
                 End Sub
 
                 Public Overloads Function Equals(source As TypeSymbol, other As TypeSymbol) As Boolean
-                    Dim visitedSource = _matcher.Visit(source)
-                    Dim visitedOther = If(_deepTranslatorOpt IsNot Nothing, _deepTranslatorOpt.Visit(other), other)
+                    Dim visitedSource = DirectCast(_matcher.Visit(source), TypeSymbol)
+                    Dim visitedOther = If(_deepTranslatorOpt IsNot Nothing, DirectCast(_deepTranslatorOpt.Visit(other), TypeSymbol), other)
 
-                    Return visitedSource = visitedOther
+                    ' If both visitedSource and visitedOther are Nothing, return false meaning that the method was not able to verify the equality.
+                    Return visitedSource IsNot Nothing AndAlso visitedOther IsNot Nothing AndAlso visitedSource.IsSameType(visitedOther, TypeCompareKind.IgnoreTupleNames)
                 End Function
             End Class
         End Class
@@ -692,6 +693,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Emit
             End Function
 
             Public Overrides Function VisitNamedType(type As NamedTypeSymbol) As Symbol
+                If type.IsTupleType Then
+                    type = type.TupleUnderlyingType
+                    Debug.Assert(Not type.IsTupleType)
+                End If
+
                 Dim originalDef As NamedTypeSymbol = type.OriginalDefinition
                 If originalDef IsNot type Then
                     Dim translatedTypeArguments = type.GetAllTypeArgumentsWithModifiers().SelectAsArray(Function(t, v) New TypeWithModifiers(DirectCast(v.Visit(t.Type), TypeSymbol),

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

@@ -14776,7 +14776,7 @@ options:=TestOptions.DebugExe, additionalRefs:=s_valueTupleRefs)
                 Next
 
                 For i = 0 To members1.Length - 1
-                    For j = 0 To members2.Length
+                    For j = 0 To members2.Length - 1
                         If i <> j Then
                             Assert.NotSame(members1(i), members2(j))
                             Assert.False(members1(i).Equals(members2(j)))
@@ -14824,7 +14824,8 @@ options:=TestOptions.DebugExe, additionalRefs:=s_valueTupleRefs)
         End Sub
 
         Private Shared Sub AssertTestDisplayString(symbols As ImmutableArray(Of Symbol), ParamArray baseLine As String())
-            AssertEx.Equal(symbols.Select(Function(s) s.ToTestDisplayString()), baseLine)
+            ' Re-ordering arguments because expected is usually first.
+            AssertEx.Equal(baseLine, symbols.Select(Function(s) s.ToTestDisplayString()))
         End Sub
 
         <Fact>

src/Compilers/VisualBasic/Test/Emit/Emit/EditAndContinue/EditAndContinueTestBase.vb

@@ -21,6 +21,8 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.UnitTests
         ' PDB reader can only be accessed from a single thread, so avoid concurrent compilation:
         Protected Shared ReadOnly ComSafeDebugDll As VisualBasicCompilationOptions = TestOptions.DebugDll.WithConcurrentBuild(False)
 
+        Protected Shared ReadOnly ValueTupleRefs As MetadataReference() = {SystemRuntimeFacadeRef, ValueTupleRef}
+
         Friend Shared ReadOnly EmptyLocalsProvider As Func(Of MethodDefinitionHandle, EditAndContinueMethodDebugInformation) = Function(token) Nothing
 
         Friend Shared Function Visualize(baseline As ModuleMetadata, ParamArray deltas As PinnedMetadata()) As String

src/Compilers/VisualBasic/Test/Emit/Emit/EditAndContinue/LocalSlotMappingTests.vb

@@ -924,5 +924,125 @@ End Class
 
         End Sub
 
+        <Fact>
+        Public Sub ComplexTypes()
+            Dim sourceText = "
+Imports System
+Imports System.Collections.Generic
+
+Class C
+    Sub G()
+        Dim <N:0>a</N:0> = New With {.Key = ""a"", .Value = New List(Of Tuple(Of Integer, Integer))()}
+        Dim <N:1>b</N:1> = (5, a)
+        Dim <N:2>c</N:2> = {b}
+    End Sub
+End Class   
+"
+            Dim source0 = MarkedSource(sourceText)
+            Dim source1 = MarkedSource(sourceText)
+            Dim source2 = MarkedSource(sourceText)
+
+            Dim compilation0 = CreateCompilationWithMscorlib(source0.Tree, options:=ComSafeDebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1.Tree)
+            Dim compilation2 = compilation1.WithSource(source2.Tree)
+
+            Dim f0 = compilation0.GetMember(Of MethodSymbol)("C.G")
+            Dim f1 = compilation1.GetMember(Of MethodSymbol)("C.G")
+            Dim f2 = compilation2.GetMember(Of MethodSymbol)("C.G")
+
+            Dim v0 = CompileAndVerify(compilation0)
+            v0.VerifyIL("C.G", "
+{
+  // Code size       42 (0x2a)
+  .maxstack  4
+  .locals init (VB$AnonymousType_0(Of String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))) V_0, //a
+                System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>) V_1, //b
+                (Integer, a As <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)() V_2) //c
+  IL_0000:  nop
+  IL_0001:  ldstr      ""a""
+  IL_0006:  newobj     ""Sub System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))..ctor()""
+  IL_000b:  newobj     ""Sub VB$AnonymousType_0(Of String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer)))..ctor(String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer)))""
+  IL_0010:  stloc.0
+  IL_0011:  ldloca.s   V_1
+  IL_0013:  ldc.i4.5
+  IL_0014:  ldloc.0
+  IL_0015:  call       ""Sub System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)..ctor(Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_001a:  ldc.i4.1
+  IL_001b:  newarr     ""System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_0020:  dup
+  IL_0021:  ldc.i4.0
+  IL_0022:  ldloc.1
+  IL_0023:  stelem     ""System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_0028:  stloc.2
+  IL_0029:  ret
+}
+")
+
+            Dim md0 = ModuleMetadata.CreateFromImage(v0.EmittedAssemblyData)
+
+            Dim generation0 = EmitBaseline.CreateInitialBaseline(md0, AddressOf v0.CreateSymReader().GetEncMethodDebugInfo)
+            Dim diff1 = compilation1.EmitDifference(
+                generation0,
+                ImmutableArray.Create(New SemanticEdit(SemanticEditKind.Update, f0, f1, GetSyntaxMapFromMarkers(source0, source1), preserveLocalVariables:=True)))
+
+            diff1.VerifyIL("C.G", "
+{
+  // Code size       42 (0x2a)
+  .maxstack  4
+  .locals init (VB$AnonymousType_0(Of String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))) V_0, //a
+                System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>) V_1, //b
+                (Integer, a As <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)() V_2) //c
+  IL_0000:  nop
+  IL_0001:  ldstr      ""a""
+  IL_0006:  newobj     ""Sub System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))..ctor()""
+  IL_000b:  newobj     ""Sub VB$AnonymousType_0(Of String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer)))..ctor(String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer)))""
+  IL_0010:  stloc.0
+  IL_0011:  ldloca.s   V_1
+  IL_0013:  ldc.i4.5
+  IL_0014:  ldloc.0
+  IL_0015:  call       ""Sub System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)..ctor(Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_001a:  ldc.i4.1
+  IL_001b:  newarr     ""System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_0020:  dup
+  IL_0021:  ldc.i4.0
+  IL_0022:  ldloc.1
+  IL_0023:  stelem     ""System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_0028:  stloc.2
+  IL_0029:  ret
+}
+")
+
+            Dim diff2 = compilation2.EmitDifference(
+                diff1.NextGeneration,
+                ImmutableArray.Create(New SemanticEdit(SemanticEditKind.Update, f1, f2, GetSyntaxMapFromMarkers(source1, source2), preserveLocalVariables:=True)))
+
+            diff2.VerifyIL("C.G", "
+{
+  // Code size       42 (0x2a)
+  .maxstack  4
+  .locals init (VB$AnonymousType_0(Of String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))) V_0, //a
+                System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>) V_1, //b
+                (Integer, a As <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)() V_2) //c
+  IL_0000:  nop
+  IL_0001:  ldstr      ""a""
+  IL_0006:  newobj     ""Sub System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))..ctor()""
+  IL_000b:  newobj     ""Sub VB$AnonymousType_0(Of String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer)))..ctor(String, System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer)))""
+  IL_0010:  stloc.0
+  IL_0011:  ldloca.s   V_1
+  IL_0013:  ldc.i4.5
+  IL_0014:  ldloc.0
+  IL_0015:  call       ""Sub System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)..ctor(Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_001a:  ldc.i4.1
+  IL_001b:  newarr     ""System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_0020:  dup
+  IL_0021:  ldc.i4.0
+  IL_0022:  ldloc.1
+  IL_0023:  stelem     ""System.ValueTuple(Of Integer, <anonymous type: Key As String, Value As System.Collections.Generic.List(Of System.Tuple(Of Integer, Integer))>)""
+  IL_0028:  stloc.2
+  IL_0029:  ret
+}
+")
+        End Sub
+
     End Class
 End Namespace

src/Compilers/VisualBasic/Test/Emit/Emit/EditAndContinue/SymbolMatcherTests.vb

@@ -512,5 +512,397 @@ End Class
             Assert.Equal("$VB$Local_x1", mappedX1.Name)
             Assert.Null(mappedX2)
         End Sub
+
+        <Fact>
+        Public Sub TupleField_TypeChange()
+            Dim source0 = "
+Class C
+{  
+    Public x As (a As Integer, b As Integer)
+}"
+            Dim source1 = "
+Class C
+{
+    Public x As (a As Integer, b As Boolean)
+}"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of FieldSymbol)("C.x")
+            Dim other = matcher.MapDefinition(member)
+            ' If a type changes within a tuple, we do not expect types to match.
+            Assert.Null(other)
+        End Sub
+
+        <Fact>
+        Public Sub TupleField_NameChange()
+
+            Dim source0 = "
+Class C
+{  
+    Public x As (a As Integer, b As Integer)
+}"
+            Dim source1 = "
+Class C
+{
+    Public x As (a As Integer, c As Integer)
+}"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of FieldSymbol)("C.x")
+            Dim other = matcher.MapDefinition(member)
+            ' Types must match because just an element name was changed.
+            Dim otherSymbol = DirectCast(other, SourceFieldSymbol)
+            Assert.NotNull(otherSymbol)
+            Assert.Equal("C.x As (a As System.Int32, b As System.Int32)", otherSymbol.ToTestDisplayString())
+        End Sub
+
+        <Fact>
+        Public Sub TupleMethod_TypeToNoTupleChange()
+            Dim source0 = "
+Class C
+    Public Function X() As (a As Integer, b As Integer)
+        Return Nothing
+    End Function
+End Class
+"
+            Dim source1 = "
+Class C
+    Public Function X() As Integer()
+        Return Nothing
+    End Function
+End Class
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of MethodSymbol)("C.X")
+            Dim other = matcher.MapDefinition(member)
+            ' Types should not match: one is tuple and another is not.
+            Assert.Null(other)
+        End Sub
+
+        <Fact>
+        Public Sub TupleMethod_TypeFromNoTupleChange()
+            Dim source0 = "
+Class C
+    Public Function X() As Integer()
+        Return Nothing
+    End Function
+End Class
+"
+            Dim source1 = "
+Class C
+    Public Function X() As (a As Integer, b As Boolean)
+        Return Nothing
+    End Function
+End Class
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of MethodSymbol)("C.X")
+            Dim other = matcher.MapDefinition(member)
+            ' Types should not match: one is tuple and another is not.
+            Assert.Null(other)
+        End Sub
+
+        <Fact>
+        Public Sub TupleMethod_TypeChange()
+            Dim source0 = "
+Class C
+    Public Function X() As (a As Integer, b As Integer)
+        Return Nothing
+    End Function
+End Class
+"
+            Dim source1 = "
+Class C
+    Public Function X() As (a As Integer, b As Boolean)
+        Return Nothing
+    End Function
+End Class
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of MethodSymbol)("C.X")
+            Dim other = matcher.MapDefinition(member)
+            ' If a type changes within a tuple, we do not expect types to match.
+            Assert.Null(other)
+        End Sub
+
+        <Fact>
+        Public Sub TupleMethod_NameChange()
+            Dim source0 = "
+Class C
+    Public Function X() As (a As Integer, b As Integer)
+        Return Nothing
+    End Function
+End Class
+"
+            Dim source1 = "
+Class C
+    Public Function X() As (a As Integer, c As Integer)
+        Return Nothing
+    End Function
+End Class
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of MethodSymbol)("C.X")
+            Dim other = matcher.MapDefinition(member)
+            ' Types must match because just an element name was changed.
+            Dim otherSymbol = DirectCast(other, SourceMemberMethodSymbol)
+            Assert.NotNull(otherSymbol)
+            Assert.Equal("Function C.X() As (a As System.Int32, b As System.Int32)", otherSymbol.ToTestDisplayString())
+        End Sub
+
+        <Fact>
+        Public Sub TupleProperty_TypeChange()
+            Dim source0 = "
+Class C
+    Public ReadOnly Property X As (a As Integer, b As Integer)
+        Get
+            Return Nothing
+        End Get
+    End Property
+End Class
+"
+            Dim source1 = "
+Class C
+    Public ReadOnly Property X As (a As Integer, b As Boolean)
+        Get
+            Return Nothing
+        End Get
+    End Property
+End Class
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of PropertySymbol)("C.X")
+            Dim other = matcher.MapDefinition(member)
+            ' If a type changes within a tuple, we do not expect types to match.
+            Assert.Null(other)
+        End Sub
+
+        <Fact>
+        Public Sub TupleProperty_NameChange()
+            Dim source0 = "
+Class C
+    Public ReadOnly Property X As (a As Integer, b As Integer)
+        Get
+            Return Nothing
+        End Get
+    End Property
+End Class
+"
+            Dim source1 = "
+Class C
+    Public ReadOnly Property X As (a As Integer, c As Integer)
+        Get
+            Return Nothing
+        End Get
+    End Property
+End Class
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of PropertySymbol)("C.X")
+            Dim other = matcher.MapDefinition(member)
+            ' Types must match because just an element name was changed.
+            Dim otherSymbol = DirectCast(other, SourcePropertySymbol)
+            Assert.NotNull(otherSymbol)
+            Assert.Equal("ReadOnly Property C.X As (a As System.Int32, b As System.Int32)", otherSymbol.ToTestDisplayString())
+        End Sub
+
+        <Fact>
+        Public Sub TupleStructField_TypeChange()
+            Dim source0 = "
+Public Structure Vector
+    Public Coordinates As (x As Integer, y As Integer)
+End Structure
+"
+            Dim source1 = "
+Public Structure Vector
+    Public Coordinates As (x As Integer, y As Integer, z As Integer)
+End Structure
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of FieldSymbol)("Vector.Coordinates")
+            Dim other = matcher.MapDefinition(member)
+            ' If a type changes within a tuple, we do not expect types to match.
+            Assert.Null(other)
+        End Sub
+
+        <Fact>
+        Public Sub TupleStructField_NameChange()
+            Dim source0 = "
+Public Structure Vector
+    Public Coordinates As (x As Integer, y As Integer)
+End Structure
+"
+            Dim source1 = "
+Public Structure Vector
+    Public Coordinates As (x As Integer, z As Integer)
+End Structure
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:= TestOptions.DebugDll, references:= ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of FieldSymbol)("Vector.Coordinates")
+            Dim other = matcher.MapDefinition(member)
+            ' Types must match because just an element name was changed.
+            Dim otherSymbol = DirectCast(other, SourceFieldSymbol)
+            Assert.NotNull(otherSymbol)
+            Assert.Equal("Vector.Coordinates As (x As System.Int32, y As System.Int32)", otherSymbol.ToTestDisplayString())
+        End Sub
+
+        <Fact>
+        Public Sub TupleDelegate_TypeChange()
+            Dim source0 = "
+Public Class C
+    Public Delegate Function F() As (Integer, Integer)
+End Class
+"
+            Dim source1 = "
+Public Class C
+    Public Delegate Function F() As (Integer, Boolean)
+End Class
+"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:= TestOptions.DebugDll, references:= ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of SourceNamedTypeSymbol)("C.F")
+            Dim other = matcher.MapDefinition(member)
+            ' Tuple delegate defines a type. We should be able to match old and new types by name.
+            Dim otherSymbol = DirectCast(other, SourceNamedTypeSymbol)
+            Assert.NotNull(otherSymbol)
+            Assert.Equal("C.F", otherSymbol.ToTestDisplayString())
+        End Sub
+
+        <Fact>
+        Public Sub TupleDeletagate_NameChange()
+            Dim source0 = "
+Public Class C
+    Public Delegate Function F() As (x as Integer, y as Integer)
+End Class
+"
+            Dim source1 = "
+Public Class C
+    Public Delegate Function F() As (x as Integer, z as Integer)
+End Class"
+            Dim compilation0 = CreateCompilationWithMscorlib(source0, options:=TestOptions.DebugDll, references:=ValueTupleRefs)
+            Dim compilation1 = compilation0.WithSource(source1)
+
+            Dim matcher = New VisualBasicSymbolMatcher(
+                Nothing,
+                compilation1.SourceAssembly,
+                New EmitContext(),
+                compilation0.SourceAssembly,
+                New EmitContext(),
+                Nothing)
+
+            Dim member = compilation1.GetMember(Of SourceNamedTypeSymbol)("C.F")
+            Dim other = matcher.MapDefinition(member)
+            ' Types must match because just an element name was changed.
+            Dim otherSymbol = DirectCast(other, SourceNamedTypeSymbol)
+            Assert.NotNull(otherSymbol)
+            Assert.Equal("C.F", otherSymbol.ToTestDisplayString())
+        End Sub
     End Class
-End Namespace
+End Namespace
\ No newline at end of file

src/Test/Utilities/Portable/Assert/AssertEx.cs

@@ -448,6 +448,10 @@ public static string GetAssertMessage<T>(IEnumerable<T> expected, IEnumerable<T>
                 {
                     itemInspector = b => $"0x{b:X2}";
                 }
+                else if (expected is IEnumerable<string>)
+                {
+                    itemInspector = new Func<T, string>(obj => (obj != null) ? string.Format("\"{0}\"", obj.ToString()) : "<null>");
+                }
                 else
                 {
                     itemInspector = new Func<T, string>(obj => (obj != null) ? obj.ToString() : "<null>");