Add unit tests for IArrayElementReferenceExpression and make the API public again

Fixes #22006

src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IObjectCreationExpression.cs

@@ -350,13 +350,13 @@ static void Main()
             Initializer: IObjectOrCollectionInitializerExpression (OperationKind.ObjectOrCollectionInitializerExpression, Type: System.Int32[]) (Syntax: '{ [0] = 1, [1] = 2 }')
                 Initializers(2):
                     ISimpleAssignmentExpression (OperationKind.SimpleAssignmentExpression, Type: System.Int32) (Syntax: '[0] = 1')
-                      Left: IArrayElementReferenceExpression (OperationKind.None) (Syntax: '[0]')
+                      Left: IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: '[0]')
                           Array reference: IInstanceReferenceExpression (OperationKind.InstanceReferenceExpression, Type: System.Int32[]) (Syntax: 'a')
                           Indices(1):
                               ILiteralExpression (OperationKind.LiteralExpression, Type: System.Int32, Constant: 0) (Syntax: '0')
                       Right: ILiteralExpression (OperationKind.LiteralExpression, Type: System.Int32, Constant: 1) (Syntax: '1')
                     ISimpleAssignmentExpression (OperationKind.SimpleAssignmentExpression, Type: System.Int32) (Syntax: '[1] = 2')
-                      Left: IArrayElementReferenceExpression (OperationKind.None) (Syntax: '[1]')
+                      Left: IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: '[1]')
                           Array reference: IInstanceReferenceExpression (OperationKind.InstanceReferenceExpression, Type: System.Int32[]) (Syntax: 'a')
                           Indices(1):
                               ILiteralExpression (OperationKind.LiteralExpression, Type: System.Int32, Constant: 1) (Syntax: '1')

src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IWhileUntilLoopStatement.cs

@@ -42,7 +42,7 @@ static void Main()
       IExpressionStatement (OperationKind.ExpressionStatement) (Syntax: 'sum += ids[i];')
         Expression: ICompoundAssignmentExpression (BinaryOperatorKind.Add) (OperationKind.CompoundAssignmentExpression, Type: System.Int32) (Syntax: 'sum += ids[i]')
             Left: ILocalReferenceExpression: sum (OperationKind.LocalReferenceExpression, Type: System.Int32) (Syntax: 'sum')
-            Right: IArrayElementReferenceExpression (OperationKind.None) (Syntax: 'ids[i]')
+            Right: IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: 'ids[i]')
                 Array reference: ILocalReferenceExpression: ids (OperationKind.LocalReferenceExpression, Type: System.Int32[]) (Syntax: 'ids')
                 Indices(1):
                     ILocalReferenceExpression: i (OperationKind.LocalReferenceExpression, Type: System.Int32) (Syntax: 'i')

src/Compilers/Core/Portable/Generated/Operations.xml.Generated.cs

@@ -311,9 +311,7 @@ public LazyArrayCreationExpression(Lazy<ImmutableArray<IOperation>> dimensionSiz
     internal abstract partial class BaseArrayElementReferenceExpression : Operation, IArrayElementReferenceExpression
     {
         protected BaseArrayElementReferenceExpression(SemanticModel semanticModel, SyntaxNode syntax, ITypeSymbol type, Optional<object> constantValue, bool isImplicit) :
-            // https://github.com/dotnet/roslyn/issues/22006
-            //base(OperationKind.ArrayElementReferenceExpression, semanticModel, syntax, type, constantValue, isImplicit)
-            base(OperationKind.None, semanticModel, syntax, type, constantValue, isImplicit)
+            base(OperationKind.ArrayElementReferenceExpression, semanticModel, syntax, type, constantValue, isImplicit)
         {
         }
 

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

@@ -11,7 +11,7 @@ namespace Microsoft.CodeAnalysis.Semantics
     /// This interface is reserved for implementation by its associated APIs. We reserve the right to
     /// change it in the future.
     /// </remarks>
-    internal interface IArrayElementReferenceExpression : IOperation // https://github.com/dotnet/roslyn/issues/22006
+    public interface IArrayElementReferenceExpression : IOperation
     {
         /// <summary>
         /// Array to be indexed.

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

@@ -190,7 +190,7 @@ public override IOperation VisitOmittedArgumentExpression(IOmittedArgumentExpres
             return new OmittedArgumentExpression(((Operation)operation).SemanticModel, operation.Syntax, operation.Type, operation.ConstantValue, operation.IsImplicit);
         }
 
-        internal override IOperation VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation, object argument)
+        public override IOperation VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation, object argument)
         {
             return new ArrayElementReferenceExpression(Visit(operation.ArrayReference), VisitArray(operation.Indices), ((Operation)operation).SemanticModel, operation.Syntax, operation.Type, operation.ConstantValue, operation.IsImplicit);
         }

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

@@ -76,9 +76,8 @@ public enum OperationKind
         ConversionExpression = 0x102,
         /// <summary>Indicates an <see cref="IInvocationExpression"/>.</summary>
         InvocationExpression = 0x103,
-        // https://github.com/dotnet/roslyn/issues/22006
-        // /// <summary>Indicates an <see cref="IArrayElementReferenceExpression"/>.</summary>
-        // ArrayElementReferenceExpression = 0x104,
+        /// <summary>Indicates an <see cref="IArrayElementReferenceExpression"/>.</summary>
+        ArrayElementReferenceExpression = 0x104,
         /// <summary>Indicates an <see cref="ILocalReferenceExpression"/>.</summary>
         LocalReferenceExpression = 0x105,
         /// <summary>Indicates an <see cref="IParameterReferenceExpression"/>.</summary>

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

@@ -189,8 +189,7 @@ public virtual void VisitOmittedArgumentExpression(IOmittedArgumentExpression op
             DefaultVisit(operation);
         }
 
-        // https://github.com/dotnet/roslyn/issues/22006
-        internal virtual void VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation)
+        public virtual void VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation)
         {
             DefaultVisit(operation);
         }
@@ -682,8 +681,7 @@ public virtual TResult VisitOmittedArgumentExpression(IOmittedArgumentExpression
             return DefaultVisit(operation, argument);
         }
 
-        // https://github.com/dotnet/roslyn/issues/22006
-        internal virtual TResult VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation, TArgument argument)
+        public virtual TResult VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation, TArgument argument)
         {
             return DefaultVisit(operation, argument);
         }

src/Compilers/Core/Portable/PublicAPI.Unshipped.txt

@@ -57,6 +57,7 @@ Microsoft.CodeAnalysis.OperationKind.AnonymousFunctionExpression = 273 -> Micros
 Microsoft.CodeAnalysis.OperationKind.AnonymousObjectCreationExpression = 287 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.Argument = 1031 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.ArrayCreationExpression = 276 -> Microsoft.CodeAnalysis.OperationKind
+Microsoft.CodeAnalysis.OperationKind.ArrayElementReferenceExpression = 260 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.ArrayInitializer = 1029 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.AwaitExpression = 279 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.BinaryOperatorExpression = 270 -> Microsoft.CodeAnalysis.OperationKind
@@ -207,6 +208,9 @@ Microsoft.CodeAnalysis.Semantics.IArgument.Value.get -> Microsoft.CodeAnalysis.I
 Microsoft.CodeAnalysis.Semantics.IArrayCreationExpression
 Microsoft.CodeAnalysis.Semantics.IArrayCreationExpression.DimensionSizes.get -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.IOperation>
 Microsoft.CodeAnalysis.Semantics.IArrayCreationExpression.Initializer.get -> Microsoft.CodeAnalysis.Semantics.IArrayInitializer
+Microsoft.CodeAnalysis.Semantics.IArrayElementReferenceExpression
+Microsoft.CodeAnalysis.Semantics.IArrayElementReferenceExpression.ArrayReference.get -> Microsoft.CodeAnalysis.IOperation
+Microsoft.CodeAnalysis.Semantics.IArrayElementReferenceExpression.Indices.get -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.IOperation>
 Microsoft.CodeAnalysis.Semantics.IArrayInitializer
 Microsoft.CodeAnalysis.Semantics.IArrayInitializer.ElementValues.get -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.IOperation>
 Microsoft.CodeAnalysis.Semantics.IAssignmentExpression
@@ -504,6 +508,7 @@ virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitAnonymousFunction
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitAnonymousObjectCreationExpression(Microsoft.CodeAnalysis.Semantics.IAnonymousObjectCreationExpression operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitArgument(Microsoft.CodeAnalysis.Semantics.IArgument operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitArrayCreationExpression(Microsoft.CodeAnalysis.Semantics.IArrayCreationExpression operation) -> void
+virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitArrayElementReferenceExpression(Microsoft.CodeAnalysis.Semantics.IArrayElementReferenceExpression operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitArrayInitializer(Microsoft.CodeAnalysis.Semantics.IArrayInitializer operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitAwaitExpression(Microsoft.CodeAnalysis.Semantics.IAwaitExpression operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitBinaryOperatorExpression(Microsoft.CodeAnalysis.Semantics.IBinaryOperatorExpression operation) -> void
@@ -590,6 +595,7 @@ virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.Vi
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitAnonymousObjectCreationExpression(Microsoft.CodeAnalysis.Semantics.IAnonymousObjectCreationExpression operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitArgument(Microsoft.CodeAnalysis.Semantics.IArgument operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitArrayCreationExpression(Microsoft.CodeAnalysis.Semantics.IArrayCreationExpression operation, TArgument argument) -> TResult
+virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitArrayElementReferenceExpression(Microsoft.CodeAnalysis.Semantics.IArrayElementReferenceExpression operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitArrayInitializer(Microsoft.CodeAnalysis.Semantics.IArrayInitializer operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitAwaitExpression(Microsoft.CodeAnalysis.Semantics.IAwaitExpression operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitBinaryOperatorExpression(Microsoft.CodeAnalysis.Semantics.IBinaryOperatorExpression operation, TArgument argument) -> TResult

src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_ArrayCreationAndInitializer.vb

@@ -278,7 +278,7 @@ End Class]]>.Value
 IArrayCreationExpression (OperationKind.ArrayCreationExpression, Type: System.Int32(), IsInvalid) (Syntax: 'New Integer(x(0)) {1, 2}')
   Dimension Sizes(1):
       IBinaryOperatorExpression (BinaryOperatorKind.Add, Checked) (OperationKind.BinaryOperatorExpression, Type: System.Int32) (Syntax: 'x(0)')
-        Left: IArrayElementReferenceExpression (OperationKind.None) (Syntax: 'x(0)')
+        Left: IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: 'x(0)')
             Array reference: ILocalReferenceExpression: x (OperationKind.LocalReferenceExpression, Type: System.Int32()) (Syntax: 'x')
             Indices(1):
                 ILiteralExpression (OperationKind.LiteralExpression, Type: System.Int32, Constant: 0) (Syntax: '0')
@@ -565,13 +565,13 @@ End Class]]>.Value
 IArrayCreationExpression (OperationKind.ArrayCreationExpression, Type: System.Int32(,)) (Syntax: 'New Integer ... ), x(1)) {}')
   Dimension Sizes(2):
       IBinaryOperatorExpression (BinaryOperatorKind.Add, Checked) (OperationKind.BinaryOperatorExpression, Type: System.Int32) (Syntax: 'x(0)')
-        Left: IArrayElementReferenceExpression (OperationKind.None) (Syntax: 'x(0)')
+        Left: IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: 'x(0)')
             Array reference: IParameterReferenceExpression: x (OperationKind.ParameterReferenceExpression, Type: System.Int32()) (Syntax: 'x')
             Indices(1):
                 ILiteralExpression (OperationKind.LiteralExpression, Type: System.Int32, Constant: 0) (Syntax: '0')
         Right: ILiteralExpression (OperationKind.LiteralExpression, Type: System.Int32, Constant: 1) (Syntax: 'x(0)')
       IBinaryOperatorExpression (BinaryOperatorKind.Add, Checked) (OperationKind.BinaryOperatorExpression, Type: System.Int32) (Syntax: 'x(1)')
-        Left: IArrayElementReferenceExpression (OperationKind.None) (Syntax: 'x(1)')
+        Left: IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: 'x(1)')
             Array reference: IParameterReferenceExpression: x (OperationKind.ParameterReferenceExpression, Type: System.Int32()) (Syntax: 'x')
             Indices(1):
                 ILiteralExpression (OperationKind.LiteralExpression, Type: System.Int32, Constant: 1) (Syntax: '1')

src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_IForLoopStatement.vb

@@ -41,7 +41,7 @@ IForToLoopStatement (LoopKind.ForTo) (OperationKind.LoopStatement) (Syntax: 'For
             Instance Receiver: null
             Arguments(1):
                 IArgument (ArgumentKind.Explicit, Matching Parameter: value) (OperationKind.Argument) (Syntax: 'myarray(i)')
-                  IArrayElementReferenceExpression (OperationKind.None) (Syntax: 'myarray(i)')
+                  IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: 'myarray(i)')
                     Array reference: ILocalReferenceExpression: myarray (OperationKind.LocalReferenceExpression, Type: System.Int32()) (Syntax: 'myarray')
                     Indices(1):
                         ILocalReferenceExpression: i (OperationKind.LocalReferenceExpression, Type: System.Int32) (Syntax: 'i')
@@ -91,7 +91,7 @@ IForToLoopStatement (LoopKind.ForTo) (OperationKind.LoopStatement) (Syntax: 'For
             Instance Receiver: null
             Arguments(1):
                 IArgument (ArgumentKind.Explicit, Matching Parameter: value) (OperationKind.Argument) (Syntax: 'myarray(i)')
-                  IArrayElementReferenceExpression (OperationKind.None) (Syntax: 'myarray(i)')
+                  IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: 'myarray(i)')
                     Array reference: ILocalReferenceExpression: myarray (OperationKind.LocalReferenceExpression, Type: System.Int32()) (Syntax: 'myarray')
                     Indices(1):
                         ILocalReferenceExpression: i (OperationKind.LocalReferenceExpression, Type: System.Int32) (Syntax: 'i')

src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_IWhileUntilLoopStatement.vb

@@ -39,7 +39,7 @@ IDoLoopStatement (DoLoopKind: DoWhileBottomLoop) (LoopKind.Do) (OperationKind.Lo
       IExpressionStatement (OperationKind.ExpressionStatement) (Syntax: 'sum += ids(i)')
         Expression: ICompoundAssignmentExpression (BinaryOperatorKind.Add, Checked) (OperationKind.CompoundAssignmentExpression, Type: System.Int32) (Syntax: 'sum += ids(i)')
             Left: ILocalReferenceExpression: sum (OperationKind.LocalReferenceExpression, Type: System.Int32) (Syntax: 'sum')
-            Right: IArrayElementReferenceExpression (OperationKind.None) (Syntax: 'ids(i)')
+            Right: IArrayElementReferenceExpression (OperationKind.ArrayElementReferenceExpression, Type: System.Int32) (Syntax: 'ids(i)')
                 Array reference: ILocalReferenceExpression: ids (OperationKind.LocalReferenceExpression, Type: System.Int32()) (Syntax: 'ids')
                 Indices(1):
                     ILocalReferenceExpression: i (OperationKind.LocalReferenceExpression, Type: System.Int32) (Syntax: 'i')

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

@@ -727,7 +727,7 @@ public override void VisitOmittedArgumentExpression(IOmittedArgumentExpression o
             LogCommonPropertiesAndNewLine(operation);
         }
 
-        internal override void VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation)
+        public override void VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation)
         {
             LogString(nameof(IArrayElementReferenceExpression));
             LogCommonPropertiesAndNewLine(operation);

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

@@ -245,7 +245,7 @@ public override void VisitOmittedArgumentExpression(IOmittedArgumentExpression o
             base.VisitOmittedArgumentExpression(operation);
         }
 
-        internal override void VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation)
+        public override void VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation)
         {
             base.VisitArrayElementReferenceExpression(operation);
         }