1 files changed, 49 insertions, 0 deletions

diff --git a/src/WixToolset.Core.Native/Msm/MsmInterop.cs b/src/WixToolset.Core.Native/Msm/MsmInterop.cs
new file mode 100644
index 00000000..d2627904
--- /dev/null
+++ b/src/WixToolset.Core.Native/Msm/MsmInterop.cs
@@ -0,0 +1,49 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Core.Native.Msm
+{
+    using System;
+    using System.Runtime.InteropServices;
+
+    /// <summary>
+    /// Merge merge modules into an MSI file.
+    /// </summary>
+    [ComImport, Guid("F94985D5-29F9-4743-9805-99BC3F35B678")]
+    public class MsmMerge2
+    {
+    }
+
+    /// <summary>
+    /// Defines the standard COM IClassFactory interface.
+    /// </summary>
+    [ComImport, Guid("00000001-0000-0000-C000-000000000046")]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    public interface IClassFactory
+    {
+        /// <summary>
+        /// 
+        /// </summary>
+        [return: MarshalAs(UnmanagedType.IUnknown)]
+        object CreateInstance(IntPtr unkOuter, [MarshalAs(UnmanagedType.LPStruct)] Guid iid);
+    }
+
+    /// <summary>
+    /// Contains native methods for merge operations.
+    /// </summary>
+    public static class MsmInterop
+    {
+        [DllImport("mergemod.dll", EntryPoint = "DllGetClassObject", PreserveSig = false)]
+        [return: MarshalAs(UnmanagedType.IUnknown)]
+        private static extern object MergeModGetClassObject([MarshalAs(UnmanagedType.LPStruct)] Guid clsid, [MarshalAs(UnmanagedType.LPStruct)] Guid iid);
+
+        /// <summary>
+        /// Load the merge object directly from a local mergemod.dll without going through COM registration.
+        /// </summary>
+        /// <returns>Merge interface.</returns>
+        public static IMsmMerge2 GetMsmMerge()
+        {
+            var classFactory = (IClassFactory)MergeModGetClassObject(typeof(MsmMerge2).GUID, typeof(IClassFactory).GUID);
+            return (IMsmMerge2)classFactory.CreateInstance(IntPtr.Zero, typeof(IMsmMerge2).GUID);
+        }
+    }
+}