Expose if an INamedTypeSymbol is a 'ComImport'

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

@@ -1473,6 +1473,8 @@ ISymbol INamedTypeSymbol.AssociatedSymbol
         /// </summary>
         INamedTypeSymbol INamedTypeSymbol.TupleUnderlyingType => this.TupleUnderlyingType;
 
+        bool INamedTypeSymbol.IsComImport => IsComImport;
+
         #endregion
 
         #region ISymbol Members

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

@@ -89,6 +89,7 @@ Microsoft.CodeAnalysis.IArrayTypeSymbol.Sizes.get -> System.Collections.Immutabl
 Microsoft.CodeAnalysis.IFieldSymbol.CorrespondingTupleField.get -> Microsoft.CodeAnalysis.IFieldSymbol
 Microsoft.CodeAnalysis.IMethodSymbol.ReturnsByRef.get -> bool
 Microsoft.CodeAnalysis.INamedTypeSymbol.GetTypeArgumentCustomModifiers(int ordinal) -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.CustomModifier>
+Microsoft.CodeAnalysis.INamedTypeSymbol.IsComImport.get -> bool
 Microsoft.CodeAnalysis.INamedTypeSymbol.TupleElements.get -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.IFieldSymbol>
 Microsoft.CodeAnalysis.INamedTypeSymbol.TupleUnderlyingType.get -> Microsoft.CodeAnalysis.INamedTypeSymbol
 Microsoft.CodeAnalysis.IOperation

src/Compilers/Core/Portable/Symbols/INamedTypeSymbol.cs

@@ -2,6 +2,8 @@
 
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Reflection;
+using System.Runtime.InteropServices;
 
 namespace Microsoft.CodeAnalysis
 {
@@ -46,6 +48,12 @@ public interface INamedTypeSymbol : ITypeSymbol
         /// </summary>
         bool IsImplicitClass { get; }
 
+        /// <summary>
+        /// Specifies that the class or interface is imported from another module.  See
+        /// <see cref="TypeAttributes.Import"/> and <see cref="ComImportAttribute"/>
+        /// </summary>
+        bool IsComImport { get; }
+
         /// <summary>
         /// Returns collection of names of members declared within this type.
         /// </summary>

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

@@ -1189,6 +1189,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
             End Get
         End Property
 
+        Private ReadOnly Property INamedTypeSymbol_IsComImport As Boolean Implements INamedTypeSymbol.IsComImport
+            Get
+                Return IsComImport
+            End Get
+        End Property
+
 #End Region
 
 #Region "ISymbol"

src/Workspaces/Core/Portable/CodeGeneration/Symbols/CodeGenerationAbstractNamedTypeSymbol.cs

@@ -32,13 +32,7 @@ internal abstract class CodeGenerationAbstractNamedTypeSymbol : CodeGenerationTy
             }
         }
 
-        public override SymbolKind Kind
-        {
-            get
-            {
-                return SymbolKind.NamedType;
-            }
-        }
+        public override SymbolKind Kind => SymbolKind.NamedType;
 
         public override void Accept(SymbolVisitor visitor)
         {
@@ -99,9 +93,8 @@ public override string MetadataName
 
         public ISymbol AssociatedSymbol { get; internal set; }
 
-        public bool MightContainExtensionMethods
-        {
-            get { return false; }
-        }
+        public bool MightContainExtensionMethods => false;
+
+        public bool IsComImport => false;
     }
 }
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