Address PR Feedback.

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

@@ -2009,36 +2009,34 @@ private IOperation CreateUsingLocalDeclarationsOperation(BoundUsingLocalDeclarat
                                                  isImplicit: false);
         }
 
-        internal IPropertySubpatternOperation CreatePropertySubpattern(BoundSubpattern subpattern)
+        internal IPropertySubpatternOperation CreatePropertySubpattern(BoundSubpattern subpattern, ITypeSymbol matchedType)
         {
             SyntaxNode syntax = subpattern.Syntax;
-            return new CSharpLazyPropertySubpatternOperation(this, subpattern, syntax, _semanticModel);
+            return new CSharpLazyPropertySubpatternOperation(this, subpattern, matchedType, syntax, _semanticModel);
         }
 
-        internal IOperation CreatePropertySubpatternMember(Symbol symbol, SyntaxNode syntax)
+        internal IOperation CreatePropertySubpatternMember(Symbol symbol, ITypeSymbol matchedType, SyntaxNode syntax)
         {
             var nameSyntax = (syntax is SubpatternSyntax subpatSyntax ? subpatSyntax.NameColon?.Name : null) ?? syntax;
-            bool isImplicit = nameSyntax != syntax;
+            bool isImplicit = nameSyntax == syntax;
             switch (symbol)
             {
                 case FieldSymbol field:
                     {
                         var constantValue = field.ConstantValue is null ? default(Optional<object>) : new Optional<object>(field.ConstantValue);
                         var receiver = new InstanceReferenceOperation(
-                            InstanceReferenceKind.PatternInput, _semanticModel, nameSyntax, field.ContainingType, constantValue, isImplicit: true);
+                            InstanceReferenceKind.PatternInput, _semanticModel, nameSyntax, matchedType, constantValue, isImplicit: true);
                         return new FieldReferenceOperation(
                             field, isDeclaration: false, receiver, _semanticModel, nameSyntax, field.Type.TypeSymbol, constantValue, isImplicit: isImplicit);
                     }
                 case PropertySymbol property:
                     {
                         var receiver = new InstanceReferenceOperation(
-                            InstanceReferenceKind.PatternInput, _semanticModel, nameSyntax, property.ContainingType, constantValue: default, isImplicit: true);
+                            InstanceReferenceKind.PatternInput, _semanticModel, nameSyntax, matchedType, constantValue: default, isImplicit: true);
                         return new PropertyReferenceOperation(
                             property, receiver, ImmutableArray<IArgumentOperation>.Empty, _semanticModel, nameSyntax, property.Type.TypeSymbol,
                             constantValue: default, isImplicit: isImplicit);
                     }
-                case null:
-                    return null;
                 default:
                     // We should expose the symbol in this case somehow:
                     // https://github.com/dotnet/roslyn/issues/33175

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

@@ -1516,7 +1516,7 @@ public override ImmutableArray<IPatternOperation> CreateDeconstructionSubpattern
         public override ImmutableArray<IPropertySubpatternOperation> CreatePropertySubpatterns()
         {
             return _boundRecursivePattern.Properties.IsDefault ? ImmutableArray<IPropertySubpatternOperation>.Empty :
-                _boundRecursivePattern.Properties.SelectAsArray((p, fac) => fac.CreatePropertySubpattern(p), _operationFactory);
+                _boundRecursivePattern.Properties.SelectAsArray((p, fac) => fac.CreatePropertySubpattern(p, MatchedType), _operationFactory);
         }
     }
 
@@ -1524,20 +1524,23 @@ internal sealed partial class CSharpLazyPropertySubpatternOperation : LazyProper
     {
         private readonly BoundSubpattern _subpattern;
         private readonly CSharpOperationFactory _operationFactory;
+        private readonly ITypeSymbol _matchedType;
 
         public CSharpLazyPropertySubpatternOperation(
             CSharpOperationFactory operationFactory,
             BoundSubpattern subpattern,
+            ITypeSymbol matchedType,
             SyntaxNode syntax,
             SemanticModel semanticModel)
-            : base(semanticModel, syntax, false)
+            : base(semanticModel, syntax, isImplicit: false)
         {
             _subpattern = subpattern;
             _operationFactory = operationFactory;
+            _matchedType = matchedType;
         }
         public override IOperation CreateMember()
         {
-            return _operationFactory.CreatePropertySubpatternMember(_subpattern.Symbol, Syntax);
+            return _operationFactory.CreatePropertySubpatternMember(_subpattern.Symbol, _matchedType, Syntax);
         }
 
         public override IPatternOperation CreatePattern()

src/Compilers/CSharp/Test/IOperation/IOperation/IOperationTests_IIsPatternExpression.cs

@@ -650,69 +650,45 @@ void M(int? x, bool b, int x2, bool b2)
 Block[B0] - Entry
     Statements (0)
     Next (Regular) Block[B1]
-        Entering: {R1} {R2}
+        Entering: {R1}
 .locals {R1}
 {
     Locals: [System.Int32? y]
-    .locals {R2}
-    {
-        CaptureIds: [0] [1]
-        Block[B1] - Block
-            Predecessors: [B0]
-            Statements (3)
-                IFlowCaptureOperation: 0 (OperationKind.FlowCapture, Type: null, IsImplicit) (Syntax: 'b')
-                  Value: 
+    Block[B1] - Block
+        Predecessors: [B0]
+        Statements (2)
+            IExpressionStatementOperation (OperationKind.ExpressionStatement, Type: null) (Syntax: 'b = x is var y;')
+              Expression: 
+                ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: System.Boolean) (Syntax: 'b = x is var y')
+                  Left: 
                     IParameterReferenceOperation: b (OperationKind.ParameterReference, Type: System.Boolean) (Syntax: 'b')
-                IFlowCaptureOperation: 1 (OperationKind.FlowCapture, Type: null, IsImplicit) (Syntax: 'x')
-                  Value: 
-                    IParameterReferenceOperation: x (OperationKind.ParameterReference, Type: System.Int32?) (Syntax: 'x')
-                IExpressionStatementOperation (OperationKind.ExpressionStatement, Type: null) (Syntax: 'b = x is var y;')
-                  Expression: 
-                    ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: System.Boolean) (Syntax: 'b = x is var y')
-                      Left: 
-                        IFlowCaptureReferenceOperation: 0 (OperationKind.FlowCaptureReference, Type: System.Boolean, IsImplicit) (Syntax: 'b')
-                      Right: 
-                        IIsPatternOperation (OperationKind.IsPattern, Type: System.Boolean) (Syntax: 'x is var y')
-                          Value: 
-                            IFlowCaptureReferenceOperation: 1 (OperationKind.FlowCaptureReference, Type: System.Int32?, IsImplicit) (Syntax: 'x')
-                          Pattern: 
-                            IDeclarationPatternOperation (OperationKind.DeclarationPattern, Type: null) (Syntax: 'var y') (InputType: System.Int32?, DeclaredSymbol: System.Int32? y, MatchesNull: True)
-            Next (Regular) Block[B2]
-                Leaving: {R2}
-                Entering: {R3}
-    }
-    .locals {R3}
-    {
-        CaptureIds: [2] [3]
-        Block[B2] - Block
-            Predecessors: [B1]
-            Statements (3)
-                IFlowCaptureOperation: 2 (OperationKind.FlowCapture, Type: null, IsImplicit) (Syntax: 'b2')
-                  Value: 
+                  Right: 
+                    IIsPatternOperation (OperationKind.IsPattern, Type: System.Boolean) (Syntax: 'x is var y')
+                      Value: 
+                        IParameterReferenceOperation: x (OperationKind.ParameterReference, Type: System.Int32?) (Syntax: 'x')
+                      Pattern: 
+                        IDeclarationPatternOperation (OperationKind.DeclarationPattern, Type: null) (Syntax: 'var y') (InputType: System.Int32?, DeclaredSymbol: System.Int32? y, MatchesNull: True)
+            IExpressionStatementOperation (OperationKind.ExpressionStatement, Type: null) (Syntax: 'b2 = x2 is 1;')
+              Expression: 
+                ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: System.Boolean) (Syntax: 'b2 = x2 is 1')
+                  Left: 
                     IParameterReferenceOperation: b2 (OperationKind.ParameterReference, Type: System.Boolean) (Syntax: 'b2')
-                IFlowCaptureOperation: 3 (OperationKind.FlowCapture, Type: null, IsImplicit) (Syntax: 'x2')
-                  Value: 
-                    IParameterReferenceOperation: x2 (OperationKind.ParameterReference, Type: System.Int32) (Syntax: 'x2')
-                IExpressionStatementOperation (OperationKind.ExpressionStatement, Type: null) (Syntax: 'b2 = x2 is 1;')
-                  Expression: 
-                    ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: System.Boolean) (Syntax: 'b2 = x2 is 1')
-                      Left: 
-                        IFlowCaptureReferenceOperation: 2 (OperationKind.FlowCaptureReference, Type: System.Boolean, IsImplicit) (Syntax: 'b2')
-                      Right: 
-                        IIsPatternOperation (OperationKind.IsPattern, Type: System.Boolean) (Syntax: 'x2 is 1')
+                  Right: 
+                    IIsPatternOperation (OperationKind.IsPattern, Type: System.Boolean) (Syntax: 'x2 is 1')
+                      Value: 
+                        IParameterReferenceOperation: x2 (OperationKind.ParameterReference, Type: System.Int32) (Syntax: 'x2')
+                      Pattern: 
+                        IConstantPatternOperation (OperationKind.ConstantPattern, Type: null) (Syntax: '1') (InputType: System.Int32)
                           Value: 
-                            IFlowCaptureReferenceOperation: 3 (OperationKind.FlowCaptureReference, Type: System.Int32, IsImplicit) (Syntax: 'x2')
-                          Pattern: 
-                            IConstantPatternOperation (OperationKind.ConstantPattern, Type: null) (Syntax: '1') (InputType: System.Int32)
-                              Value: 
-                                ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1) (Syntax: '1')
-            Next (Regular) Block[B3]
-                Leaving: {R3} {R1}
-    }
+                            ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1) (Syntax: '1')
+        Next (Regular) Block[B2]
+            Leaving: {R1}
 }
-Block[B3] - Exit
-    Predecessors: [B2]
-    Statements (0)";
+Block[B2] - Exit
+    Predecessors: [B1]
+    Statements (0)
+";
+
             var expectedDiagnostics = DiagnosticDescription.None;
 
             VerifyFlowGraphAndDiagnosticsForTest<BlockSyntax>(source, expectedFlowGraph, expectedDiagnostics);
@@ -731,6 +707,42 @@ void M((int X, int Y)? x, bool b)
     }/*</bind>*/
 }
 ";
+
+            var compilation = CreateCompilation(source);
+            compilation.VerifyDiagnostics();
+
+            string expectedOperationTree = @"
+IBlockOperation (1 statements, 2 locals) (OperationKind.Block, Type: null) (Syntax: '{ ... }')
+  Locals: Local_1: (System.Int32 X, System.Int32 Y) p
+    Local_2: System.Int32 z
+  IExpressionStatementOperation (OperationKind.ExpressionStatement, Type: null) (Syntax: 'b = x is (1 ...  var z } p;')
+    Expression: 
+      ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: System.Boolean) (Syntax: 'b = x is (1 ... : var z } p')
+        Left: 
+          IParameterReferenceOperation: b (OperationKind.ParameterReference, Type: System.Boolean) (Syntax: 'b')
+        Right: 
+          IIsPatternOperation (OperationKind.IsPattern, Type: System.Boolean) (Syntax: 'x is (1, _) ... : var z } p')
+            Value: 
+              IParameterReferenceOperation: x (OperationKind.ParameterReference, Type: (System.Int32 X, System.Int32 Y)?) (Syntax: 'x')
+            Pattern: 
+              IRecursivePatternOperation (OperationKind.RecursivePattern, Type: null) (Syntax: '(1, _) { It ... : var z } p') (InputType: (System.Int32 X, System.Int32 Y)?, DeclaredSymbol: (System.Int32 X, System.Int32 Y) p, MatchedType: (System.Int32 X, System.Int32 Y), DeconstructSymbol: null)
+                DeconstructionSubpatterns (2):
+                    IConstantPatternOperation (OperationKind.ConstantPattern, Type: null) (Syntax: '1') (InputType: System.Int32)
+                      Value: 
+                        ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1) (Syntax: '1')
+                    IDiscardPatternOperation (OperationKind.DiscardPattern, Type: null) (Syntax: '_') (InputType: System.Int32)
+                PropertySubpatterns (1):
+                    IPropertySubpatternOperation (OperationKind.None, Type: null) (Syntax: 'Item1: var z')
+                      Member: 
+                        IFieldReferenceOperation: System.Int32 (System.Int32 X, System.Int32 Y).Item1 (OperationKind.FieldReference, Type: System.Int32) (Syntax: 'Item1')
+                          Instance Receiver: 
+                            IInstanceReferenceOperation (ReferenceKind: PatternInput) (OperationKind.InstanceReference, Type: (System.Int32 X, System.Int32 Y), IsImplicit) (Syntax: 'Item1')
+                      Pattern: 
+                        IDeclarationPatternOperation (OperationKind.DeclarationPattern, Type: null) (Syntax: 'var z') (InputType: System.Int32, DeclaredSymbol: System.Int32 z, MatchesNull: True)
+";
+
+            VerifyOperationTreeForTest<BlockSyntax>(compilation, expectedOperationTree);
+
             string expectedFlowGraph = @"
 Block[B0] - Entry
     Statements (0)
@@ -739,25 +751,18 @@ void M((int X, int Y)? x, bool b)
 .locals {R1}
 {
     Locals: [(System.Int32 X, System.Int32 Y) p] [System.Int32 z]
-    CaptureIds: [0] [1]
     Block[B1] - Block
         Predecessors: [B0]
-        Statements (3)
-            IFlowCaptureOperation: 0 (OperationKind.FlowCapture, Type: null, IsImplicit) (Syntax: 'b')
-              Value: 
-                IParameterReferenceOperation: b (OperationKind.ParameterReference, Type: System.Boolean) (Syntax: 'b')
-            IFlowCaptureOperation: 1 (OperationKind.FlowCapture, Type: null, IsImplicit) (Syntax: 'x')
-              Value: 
-                IParameterReferenceOperation: x (OperationKind.ParameterReference, Type: (System.Int32 X, System.Int32 Y)?) (Syntax: 'x')
+        Statements (1)
             IExpressionStatementOperation (OperationKind.ExpressionStatement, Type: null) (Syntax: 'b = x is (1 ...  var z } p;')
               Expression: 
                 ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: System.Boolean) (Syntax: 'b = x is (1 ... : var z } p')
                   Left: 
-                    IFlowCaptureReferenceOperation: 0 (OperationKind.FlowCaptureReference, Type: System.Boolean, IsImplicit) (Syntax: 'b')
+                    IParameterReferenceOperation: b (OperationKind.ParameterReference, Type: System.Boolean) (Syntax: 'b')
                   Right: 
                     IIsPatternOperation (OperationKind.IsPattern, Type: System.Boolean) (Syntax: 'x is (1, _) ... : var z } p')
                       Value: 
-                        IFlowCaptureReferenceOperation: 1 (OperationKind.FlowCaptureReference, Type: (System.Int32 X, System.Int32 Y)?, IsImplicit) (Syntax: 'x')
+                        IParameterReferenceOperation: x (OperationKind.ParameterReference, Type: (System.Int32 X, System.Int32 Y)?) (Syntax: 'x')
                       Pattern: 
                         IRecursivePatternOperation (OperationKind.RecursivePattern, Type: null) (Syntax: '(1, _) { It ... : var z } p') (InputType: (System.Int32 X, System.Int32 Y)?, DeclaredSymbol: (System.Int32 X, System.Int32 Y) p, MatchedType: (System.Int32 X, System.Int32 Y), DeconstructSymbol: null)
                           DeconstructionSubpatterns (2):
@@ -768,9 +773,9 @@ void M((int X, int Y)? x, bool b)
                           PropertySubpatterns (1):
                               IPropertySubpatternOperation (OperationKind.None, Type: null) (Syntax: 'Item1: var z')
                                 Member: 
-                                  IFieldReferenceOperation: System.Int32 (System.Int32 X, System.Int32 Y).Item1 (OperationKind.FieldReference, Type: System.Int32, IsImplicit) (Syntax: 'Item1')
+                                  IFieldReferenceOperation: System.Int32 (System.Int32 X, System.Int32 Y).Item1 (OperationKind.FieldReference, Type: System.Int32) (Syntax: 'Item1')
                                     Instance Receiver: 
-                                      IFlowCaptureReferenceOperation: 1 (OperationKind.FlowCaptureReference, Type: (System.Int32 X, System.Int32 Y)?, IsImplicit) (Syntax: 'x')
+                                      IInstanceReferenceOperation (ReferenceKind: PatternInput) (OperationKind.InstanceReference, Type: (System.Int32 X, System.Int32 Y), IsImplicit) (Syntax: 'Item1')
                                 Pattern: 
                                   IDeclarationPatternOperation (OperationKind.DeclarationPattern, Type: null) (Syntax: 'var z') (InputType: System.Int32, DeclaredSymbol: System.Int32 z, MatchesNull: True)
         Next (Regular) Block[B2]
@@ -779,6 +784,92 @@ void M((int X, int Y)? x, bool b)
 Block[B2] - Exit
     Predecessors: [B1]
     Statements (0)";
+
+            VerifyFlowGraphForTest<BlockSyntax>(compilation, expectedFlowGraph);
+        }
+
+        [CompilerTrait(CompilerFeature.IOperation, CompilerFeature.Dataflow, CompilerFeature.Patterns)]
+        [Fact]
+        public void IsPattern_NoControlFlow_03()
+        {
+            string source = @"
+class C
+{
+    void M((int X, (int Y, int Z))? tuple, bool b)
+    /*<bind>*/{
+        b = tuple is (1, _) { Item1: var x, Item2: { Y: 1, Z: var z } } p;
+    }/*</bind>*/
+}
+";
+
+            string expectedFlowGraph = @"
+Block[B0] - Entry
+    Statements (0)
+    Next (Regular) Block[B1]
+        Entering: {R1}
+.locals {R1}
+{
+    Locals: [(System.Int32 X, (System.Int32 Y, System.Int32 Z)) p] [System.Int32 x] [System.Int32 z]
+    Block[B1] - Block
+        Predecessors: [B0]
+        Statements (1)
+            IExpressionStatementOperation (OperationKind.ExpressionStatement, Type: null) (Syntax: 'b = tuple i ... ar z } } p;')
+              Expression: 
+                ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: System.Boolean) (Syntax: 'b = tuple i ... var z } } p')
+                  Left: 
+                    IParameterReferenceOperation: b (OperationKind.ParameterReference, Type: System.Boolean) (Syntax: 'b')
+                  Right: 
+                    IIsPatternOperation (OperationKind.IsPattern, Type: System.Boolean) (Syntax: 'tuple is (1 ... var z } } p')
+                      Value: 
+                        IParameterReferenceOperation: tuple (OperationKind.ParameterReference, Type: (System.Int32 X, (System.Int32 Y, System.Int32 Z))?) (Syntax: 'tuple')
+                      Pattern: 
+                        IRecursivePatternOperation (OperationKind.RecursivePattern, Type: null) (Syntax: '(1, _) { It ... var z } } p') (InputType: (System.Int32 X, (System.Int32 Y, System.Int32 Z))?, DeclaredSymbol: (System.Int32 X, (System.Int32 Y, System.Int32 Z)) p, MatchedType: (System.Int32 X, (System.Int32 Y, System.Int32 Z)), DeconstructSymbol: null)
+                          DeconstructionSubpatterns (2):
+                              IConstantPatternOperation (OperationKind.ConstantPattern, Type: null) (Syntax: '1') (InputType: System.Int32)
+                                Value: 
+                                  ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1) (Syntax: '1')
+                              IDiscardPatternOperation (OperationKind.DiscardPattern, Type: null) (Syntax: '_') (InputType: (System.Int32 Y, System.Int32 Z))
+                          PropertySubpatterns (2):
+                              IPropertySubpatternOperation (OperationKind.None, Type: null) (Syntax: 'Item1: var x')
+                                Member: 
+                                  IFieldReferenceOperation: System.Int32 (System.Int32 X, (System.Int32 Y, System.Int32 Z)).Item1 (OperationKind.FieldReference, Type: System.Int32) (Syntax: 'Item1')
+                                    Instance Receiver: 
+                                      IInstanceReferenceOperation (ReferenceKind: PatternInput) (OperationKind.InstanceReference, Type: (System.Int32 X, (System.Int32 Y, System.Int32 Z)), IsImplicit) (Syntax: 'Item1')
+                                Pattern: 
+                                  IDeclarationPatternOperation (OperationKind.DeclarationPattern, Type: null) (Syntax: 'var x') (InputType: System.Int32, DeclaredSymbol: System.Int32 x, MatchesNull: True)
+                              IPropertySubpatternOperation (OperationKind.None, Type: null) (Syntax: 'Item2: { Y: ...  Z: var z }')
+                                Member: 
+                                  IFieldReferenceOperation: (System.Int32 Y, System.Int32 Z) (System.Int32 X, (System.Int32 Y, System.Int32 Z)).Item2 (OperationKind.FieldReference, Type: (System.Int32 Y, System.Int32 Z)) (Syntax: 'Item2')
+                                    Instance Receiver: 
+                                      IInstanceReferenceOperation (ReferenceKind: PatternInput) (OperationKind.InstanceReference, Type: (System.Int32 X, (System.Int32 Y, System.Int32 Z)), IsImplicit) (Syntax: 'Item2')
+                                Pattern: 
+                                  IRecursivePatternOperation (OperationKind.RecursivePattern, Type: null) (Syntax: '{ Y: 1, Z: var z }') (InputType: (System.Int32 Y, System.Int32 Z), DeclaredSymbol: null, MatchedType: (System.Int32 Y, System.Int32 Z), DeconstructSymbol: null)
+                                    DeconstructionSubpatterns (0)
+                                    PropertySubpatterns (2):
+                                        IPropertySubpatternOperation (OperationKind.None, Type: null) (Syntax: 'Y: 1')
+                                          Member: 
+                                            IFieldReferenceOperation: System.Int32 (System.Int32 Y, System.Int32 Z).Y (OperationKind.FieldReference, Type: System.Int32) (Syntax: 'Y')
+                                              Instance Receiver: 
+                                                IInstanceReferenceOperation (ReferenceKind: PatternInput) (OperationKind.InstanceReference, Type: (System.Int32 Y, System.Int32 Z), IsImplicit) (Syntax: 'Y')
+                                          Pattern: 
+                                            IConstantPatternOperation (OperationKind.ConstantPattern, Type: null) (Syntax: '1') (InputType: System.Int32)
+                                              Value: 
+                                                ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1) (Syntax: '1')
+                                        IPropertySubpatternOperation (OperationKind.None, Type: null) (Syntax: 'Z: var z')
+                                          Member: 
+                                            IFieldReferenceOperation: System.Int32 (System.Int32 Y, System.Int32 Z).Z (OperationKind.FieldReference, Type: System.Int32) (Syntax: 'Z')
+                                              Instance Receiver: 
+                                                IInstanceReferenceOperation (ReferenceKind: PatternInput) (OperationKind.InstanceReference, Type: (System.Int32 Y, System.Int32 Z), IsImplicit) (Syntax: 'Z')
+                                          Pattern: 
+                                            IDeclarationPatternOperation (OperationKind.DeclarationPattern, Type: null) (Syntax: 'var z') (InputType: System.Int32, DeclaredSymbol: System.Int32 z, MatchesNull: True)
+        Next (Regular) Block[B2]
+            Leaving: {R1}
+}
+Block[B2] - Exit
+    Predecessors: [B1]
+    Statements (0)
+";
+
             var expectedDiagnostics = DiagnosticDescription.None;
 
             VerifyFlowGraphAndDiagnosticsForTest<BlockSyntax>(source, expectedFlowGraph, expectedDiagnostics);
@@ -913,7 +1004,7 @@ void M((int X, int Y) tuple, bool b)
       PropertySubpatterns (1):
           IPropertySubpatternOperation (OperationKind.None, Type: null) (Syntax: 'Item1: int x')
             Member: 
-              IFieldReferenceOperation: System.Int32 (System.Int32 X, System.Int32 Y).Item1 (OperationKind.FieldReference, Type: System.Int32, IsImplicit) (Syntax: 'Item1')
+              IFieldReferenceOperation: System.Int32 (System.Int32 X, System.Int32 Y).Item1 (OperationKind.FieldReference, Type: System.Int32) (Syntax: 'Item1')
                 Instance Receiver: 
                   IInstanceReferenceOperation (ReferenceKind: PatternInput) (OperationKind.InstanceReference, Type: (System.Int32 X, System.Int32 Y), IsImplicit) (Syntax: 'Item1')
             Pattern: 
@@ -924,7 +1015,7 @@ void M((int X, int Y) tuple, bool b)
             VerifyOperationTreeAndDiagnosticsForTest<IsPatternExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
         }
 
-        [CompilerTrait(CompilerFeature.IOperation, CompilerFeature.Dataflow, CompilerFeature.Patterns)]
+        [CompilerTrait(CompilerFeature.IOperation, CompilerFeature.Patterns)]
         [Fact]
         public void IsPattern_BadRecursivePattern_01()
         {
@@ -953,7 +1044,8 @@ void M((int X, int Y) tuple, bool b)
       PropertySubpatterns (1):
           IPropertySubpatternOperation (OperationKind.None, Type: null, IsInvalid) (Syntax: 'NotFound: int x')
             Member: 
-              null
+              IInvalidOperation (OperationKind.Invalid, Type: null, IsInvalid, IsImplicit) (Syntax: 'NotFound')
+                Children(0)
             Pattern: 
               IDeclarationPatternOperation (OperationKind.DeclarationPattern, Type: null) (Syntax: 'int x') (InputType: ?, DeclaredSymbol: System.Int32 x, MatchesNull: False)
 ";
@@ -966,6 +1058,79 @@ void M((int X, int Y) tuple, bool b)
             VerifyOperationTreeAndDiagnosticsForTest<IsPatternExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
         }
 
+        [CompilerTrait(CompilerFeature.IOperation, CompilerFeature.Patterns)]
+        [Fact]
+        public void IsPattern_BadRecursivePattern_02()
+        {
+            var vbSource = @"
+Public Class C1
+    Public Property Prop(index As Integer) As Integer
+        Get
+            Return 1
+        End Get
+        Set
+        End Set
+    End Property
+End Class
+";
+
+            var vbCompilation = CreateVisualBasicCompilation(vbSource);
+
+            var source = @"
+class C
+{
+    void M1(object o, bool b)
+    {
+        b = /*<bind>*/o is C1 { Prop[1]: var x }/*</bind>*/;
+    }
+}";
+
+            var compilation = CreateCompilation(source, new[] { vbCompilation.EmitToImageReference() });
+            compilation.VerifyDiagnostics(
+                // (6,33): error CS8503: A property subpattern requires a reference to the property or field to be matched, e.g. '{ Name: Prop[1] }'
+                //         b = /*<bind>*/o is C1 { Prop[1]: var x }/*</bind>*/;
+                Diagnostic(ErrorCode.ERR_PropertyPatternNameMissing, "Prop[1]").WithArguments("Prop[1]").WithLocation(6, 33),
+                // (6,33): error CS0103: The name 'Prop' does not exist in the current context
+                //         b = /*<bind>*/o is C1 { Prop[1]: var x }/*</bind>*/;
+                Diagnostic(ErrorCode.ERR_NameNotInContext, "Prop").WithArguments("Prop").WithLocation(6, 33),
+                // (6,40): error CS1003: Syntax error, ',' expected
+                //         b = /*<bind>*/o is C1 { Prop[1]: var x }/*</bind>*/;
+                Diagnostic(ErrorCode.ERR_SyntaxError, ":").WithArguments(",", ":").WithLocation(6, 40),
+                // (6,42): error CS1003: Syntax error, ',' expected
+                //         b = /*<bind>*/o is C1 { Prop[1]: var x }/*</bind>*/;
+                Diagnostic(ErrorCode.ERR_SyntaxError, "var").WithArguments(",", "").WithLocation(6, 42));
+
+            var expectedOperationTree = @"
+IIsPatternOperation (OperationKind.IsPattern, Type: System.Boolean, IsInvalid) (Syntax: 'o is C1 { P ... 1]: var x }')
+  Value: 
+    IParameterReferenceOperation: o (OperationKind.ParameterReference, Type: System.Object) (Syntax: 'o')
+  Pattern: 
+    IRecursivePatternOperation (OperationKind.RecursivePattern, Type: null, IsInvalid) (Syntax: 'C1 { Prop[1]: var x }') (InputType: System.Object, DeclaredSymbol: null, MatchedType: C1, DeconstructSymbol: null)
+      DeconstructionSubpatterns (0)
+      PropertySubpatterns (2):
+          IPropertySubpatternOperation (OperationKind.None, Type: null, IsInvalid) (Syntax: 'Prop[1]')
+            Member: 
+              IInvalidOperation (OperationKind.Invalid, Type: null, IsInvalid, IsImplicit) (Syntax: 'Prop[1]')
+                Children(0)
+            Pattern: 
+              IConstantPatternOperation (OperationKind.ConstantPattern, Type: null, IsInvalid) (Syntax: 'Prop[1]') (InputType: ?)
+                Value: 
+                  IInvalidOperation (OperationKind.Invalid, Type: ?, IsInvalid) (Syntax: 'Prop[1]')
+                    Children(2):
+                        ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1, IsInvalid) (Syntax: '1')
+                        IInvalidOperation (OperationKind.Invalid, Type: ?, IsInvalid) (Syntax: 'Prop')
+                          Children(0)
+          IPropertySubpatternOperation (OperationKind.None, Type: null, IsInvalid) (Syntax: 'var x')
+            Member: 
+              IInvalidOperation (OperationKind.Invalid, Type: null, IsInvalid, IsImplicit) (Syntax: 'var x')
+                Children(0)
+            Pattern: 
+              IDeclarationPatternOperation (OperationKind.DeclarationPattern, Type: null, IsInvalid) (Syntax: 'var x') (InputType: ?, DeclaredSymbol: ? x, MatchesNull: True)
+";
+
+            VerifyOperationTreeForTest<IsPatternExpressionSyntax>(compilation, expectedOperationTree);
+        }
+
         [CompilerTrait(CompilerFeature.IOperation, CompilerFeature.Dataflow, CompilerFeature.Patterns)]
         [Fact]
         public void IsPattern_ControlFlowInPattern()

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

@@ -5818,7 +5818,7 @@ IArrayInitializerOperation popAndAssembleArrayInitializerValues(IArrayInitialize
 
         public override IOperation VisitInstanceReference(IInstanceReferenceOperation operation, int? captureIdForResult)
         {
-            if (operation.ReferenceKind == InstanceReferenceKind.ImplicitReceiver || operation.ReferenceKind == InstanceReferenceKind.PatternInput)
+            if (operation.ReferenceKind == InstanceReferenceKind.ImplicitReceiver)
             {
                 // When we're in an object or collection initializer, we need to replace the instance reference with a reference to the object being initialized
                 Debug.Assert(operation.IsImplicit);
@@ -6419,14 +6419,12 @@ public override IOperation VisitDefaultValue(IDefaultValueOperation operation, i
         public override IOperation VisitIsPattern(IIsPatternOperation operation, int? captureIdForResult)
         {
             EvalStackFrame frame = PushStackFrame();
-            var capturedValue = VisitAndCapture(operation.Value);
-            var previousImplicitInstance = _currentImplicitInstance;
-            _currentImplicitInstance = new ImplicitInstanceInfo(capturedValue);
+            PushOperand(Visit(operation.Value));
             var visitedPattern = (IPatternOperation)Visit(operation.Pattern);
-            _currentImplicitInstance = previousImplicitInstance;
+            IOperation visitedValue = PopOperand();
             PopStackFrame(frame);
-            return new IsPatternOperation(capturedValue, visitedPattern, semanticModel: null,
-                                          operation.Syntax, operation.Type, operation.ConstantValue, IsImplicit(operation));
+            return new IsPatternOperation(visitedValue, visitedPattern, semanticModel: null,
+                                           operation.Syntax, operation.Type, operation.ConstantValue, IsImplicit(operation));
         }
 
         public override IOperation VisitInvalid(IInvalidOperation operation, int? captureIdForResult)
@@ -6630,14 +6628,11 @@ public override IOperation VisitSwitchExpression(ISwitchExpressionOperation oper
             RegionBuilder resultCaptureRegion = _currentRegion;
             int captureOutput = captureIdForResult ?? GetNextCaptureId(resultCaptureRegion);
             var capturedInput = VisitAndCapture(operation.Value);
-            var previousImplicitInstance = _currentImplicitInstance;
-            var switchImplicitInstance = new ImplicitInstanceInfo(capturedInput);
             var afterSwitch = new BasicBlockBuilder(BasicBlockKind.Block);
 
             foreach (var arm in operation.Arms)
             {
                 // START scope (arm locals)
-                _currentImplicitInstance = switchImplicitInstance;
                 var armScopeRegion = new RegionBuilder(ControlFlowRegionKind.LocalLifetime, locals: arm.Locals);
                 EnterRegion(armScopeRegion);
                 var afterArm = new BasicBlockBuilder(BasicBlockKind.Block);
@@ -6663,8 +6658,6 @@ public override IOperation VisitSwitchExpression(ISwitchExpressionOperation oper
                     PopStackFrameAndLeaveRegion(frame);
                 }
 
-                _currentImplicitInstance = previousImplicitInstance;
-
                 // captureOutput = e
                 VisitAndCapture(arm.Value, captureOutput);
 

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

@@ -552,7 +552,7 @@ internal override IOperation VisitRecursivePattern(IRecursivePatternOperation op
         internal override IOperation VisitPropertySubpattern(IPropertySubpatternOperation operation, object argument)
         {
             return new PropertySubpatternOperation(
-                semanticModel: null,
+                semanticModel: ((Operation)operation).OwningSemanticModel,
                 operation.Syntax,
                 operation.IsImplicit,
                 Visit(operation.Member),

src/Test/Utilities/Portable/Compilation/ControlFlowGraphVerifier.cs

@@ -1728,14 +1728,16 @@ private static bool CanBeInControlFlowGraph(IOperation n)
 
                 case OperationKind.InstanceReference:
                     // Implicit instance receivers, except for anonymous type creations, are expected to have been removed when dealing with creations.
-                    return ((IInstanceReferenceOperation)n).ReferenceKind == InstanceReferenceKind.ContainingTypeInstance ||
-                        ((IInstanceReferenceOperation)n).ReferenceKind == InstanceReferenceKind.ImplicitReceiver &&
-                        n.Type.IsAnonymousType &&
-                        n.Parent is IPropertyReferenceOperation propertyReference &&
-                        propertyReference.Instance == n &&
-                        propertyReference.Parent is ISimpleAssignmentOperation simpleAssignment &&
-                        simpleAssignment.Target == propertyReference &&
-                        simpleAssignment.Parent.Kind == OperationKind.AnonymousObjectCreation;
+                    var instanceReference = (IInstanceReferenceOperation)n;
+                    return instanceReference.ReferenceKind == InstanceReferenceKind.ContainingTypeInstance ||
+                        instanceReference.ReferenceKind == InstanceReferenceKind.PatternInput ||
+                        (instanceReference.ReferenceKind == InstanceReferenceKind.ImplicitReceiver &&
+                         n.Type.IsAnonymousType &&
+                         n.Parent is IPropertyReferenceOperation propertyReference &&
+                         propertyReference.Instance == n &&
+                         propertyReference.Parent is ISimpleAssignmentOperation simpleAssignment &&
+                         simpleAssignment.Target == propertyReference &&
+                         simpleAssignment.Parent.Kind == OperationKind.AnonymousObjectCreation);
 
                 case OperationKind.None:
                     return !(n is IPlaceholderOperation);

src/Test/Utilities/Portable/Compilation/TestOperationVisitor.cs

@@ -1197,12 +1197,10 @@ internal override void VisitRecursivePattern(IRecursivePatternOperation operatio
 
         internal override void VisitPropertySubpattern(IPropertySubpatternOperation operation)
         {
-            Assert.True(operation.Member is IMemberReferenceOperation);
+            Assert.True(operation.Member is IMemberReferenceOperation || operation.Member is IInvalidOperation);
             var member = (IMemberReferenceOperation)operation.Member;
             switch (member.Member)
             {
-                case null: // error case
-                    break;
                 case IFieldSymbol field:
                 case IPropertySymbol prop:
                 case IErrorTypeSymbol error: