Add more docs for new COM source generator types (#88627)

Author: jkoritzinsky

src/libraries/System.Runtime.InteropServices/src/System/Runtime/InteropServices/Marshalling/ComInterfaceMarshaller.cs

@@ -6,7 +6,7 @@
 namespace System.Runtime.InteropServices.Marshalling
 {
     /// <summary>
-    /// COM interface marshaller using a StrategyBasedComWrappers instance
+    /// COM interface marshaller using a <see cref="StrategyBasedComWrappers" /> instance
     /// </summary>
     /// <remarks>
     /// This marshaller will always pass the <see cref="CreateObjectFlags.Unwrap"/> flag
@@ -22,6 +22,11 @@ public static unsafe class ComInterfaceMarshaller<T>
     {
         private static readonly Guid? TargetInterfaceIID = StrategyBasedComWrappers.DefaultIUnknownInterfaceDetailsStrategy.GetIUnknownDerivedDetails(typeof(T).TypeHandle)?.Iid;
 
+        /// <summary>
+        /// Convert a managed object to a COM interface pointer for the COM interface represented by <typeparamref name="T"/>.
+        /// </summary>
+        /// <param name="managed">The managed object</param>
+        /// <returns>The COM interface pointer</returns>
         public static void* ConvertToUnmanaged(T? managed)
         {
             if (managed == null)
@@ -35,6 +40,13 @@ public static unsafe class ComInterfaceMarshaller<T>
             return CastIUnknownToInterfaceType(unknown);
         }
 
+        /// <summary>
+        /// Convert a COM interface pointer to a managed object.
+        /// </summary>
+        /// <param name="unmanaged">The COM interface pointer</param>
+        /// <remarks>
+        /// If the passed in COM interface pointer wraps a managed object, this method returns the underlying object.
+        /// </remarks>
         public static T? ConvertToManaged(void* unmanaged)
         {
             if (unmanaged == null)
@@ -44,6 +56,10 @@ public static unsafe class ComInterfaceMarshaller<T>
             return (T)StrategyBasedComWrappers.DefaultMarshallingInstance.GetOrCreateObjectForComInstance((nint)unmanaged, CreateObjectFlags.Unwrap);
         }
 
+        /// <summary>
+        /// Release a reference to the COM interface pointer.
+        /// </summary>
+        /// <param name="unmanaged">A COM interface pointer.</param>
         public static void Free(void* unmanaged)
         {
             if (unmanaged != null)

src/libraries/System.Runtime.InteropServices/src/System/Runtime/InteropServices/Marshalling/ComObject.cs

@@ -30,6 +30,9 @@ internal ComObject(IIUnknownInterfaceDetailsStrategy interfaceDetailsStrategy, I
             _instancePointer = IUnknownStrategy.CreateInstancePointer(thisPointer);
         }
 
+        /// <summary>
+        /// Release all references to the underlying COM object.
+        /// </summary>
         ~ComObject()
         {
             CacheStrategy.Clear(IUnknownStrategy);
@@ -54,11 +57,11 @@ internal ComObject(IIUnknownInterfaceDetailsStrategy interfaceDetailsStrategy, I
         internal bool UniqueInstance { get; init; }
 
         /// <summary>
-        /// Releases all references owned by this ComObject if it is a unique instance.
+        /// Releases all references owned by this <see cref="ComObject" /> if it is a unique instance.
         /// </summary>
         /// <remarks>
-        /// This method does nothing if the ComObject was not created with
-        /// CreateObjectFlags.UniqueInstance.
+        /// This method does nothing if the <see cref="ComObject" /> was not created with
+        /// <see cref="CreateObjectFlags.UniqueInstance" />.
         /// </remarks>
         public void FinalRelease()
         {

src/libraries/System.Runtime.InteropServices/src/System/Runtime/InteropServices/Marshalling/GeneratedComClassAttribute.cs

@@ -3,6 +3,12 @@
 
 namespace System.Runtime.InteropServices.Marshalling
 {
+    /// <summary>
+    /// Specifies that code should be generated to enable exposing the attributed class to COM.
+    /// </summary>
+    /// <remarks>
+    /// This attribute is only valid on types that implement at least one <see cref="GeneratedComInterfaceAttribute"/>-attributed interface.
+    /// </remarks>
     [AttributeUsage(AttributeTargets.Class)]
     public sealed class GeneratedComClassAttribute : Attribute
     {

src/libraries/System.Runtime.InteropServices/src/System/Runtime/InteropServices/Marshalling/GeneratedComInterfaceAttribute.cs

@@ -3,6 +3,9 @@
 
 namespace System.Runtime.InteropServices.Marshalling
 {
+    /// <summary>
+    /// Specifies that the attributed type is a COM interface and that the source generator should generate code for it.
+    /// </summary>
     [AttributeUsage(AttributeTargets.Interface)]
     public class GeneratedComInterfaceAttribute : Attribute
     {

src/libraries/System.Runtime.InteropServices/src/System/Runtime/InteropServices/Marshalling/UniqueComInterfaceMarshaller.cs

@@ -21,6 +21,11 @@ namespace System.Runtime.InteropServices.Marshalling
     [CustomMarshaller(typeof(CustomMarshallerAttribute.GenericPlaceholder), MarshalMode.Default, typeof(UniqueComInterfaceMarshaller<>))]
     public static unsafe class UniqueComInterfaceMarshaller<T>
     {
+        /// <summary>
+        /// Convert a managed object to a COM interface pointer for the COM interface represented by <typeparamref name="T"/>.
+        /// </summary>
+        /// <param name="managed">The managed object</param>
+        /// <returns>The COM interface pointer</returns>
         public static void* ConvertToUnmanaged(T? managed)
         {
             if (managed == null)
@@ -34,6 +39,15 @@ public static unsafe class UniqueComInterfaceMarshaller<T>
             return ComInterfaceMarshaller<T>.CastIUnknownToInterfaceType(unknown);
         }
 
+
+        /// <summary>
+        /// Convert a COM interface pointer to a managed object.
+        /// </summary>
+        /// <param name="unmanaged">The COM interface pointer</param>
+        /// <returns>A managed object that represents the passed in COM interface pointer.</returns>
+        /// <remarks>
+        /// If the passed in COM interface pointer wraps a managed object, this method returns the underlying object.
+        /// </remarks>
         public static T? ConvertToManaged(void* unmanaged)
         {
             if (unmanaged == null)
@@ -43,6 +57,11 @@ public static unsafe class UniqueComInterfaceMarshaller<T>
             return (T)StrategyBasedComWrappers.DefaultMarshallingInstance.GetOrCreateObjectForComInstance((nint)unmanaged, CreateObjectFlags.Unwrap | CreateObjectFlags.UniqueInstance);
         }
 
+
+        /// <summary>
+        /// Release a reference to the COM interface pointer.
+        /// </summary>
+        /// <param name="unmanaged">A COM interface pointer.</param>
         public static void Free(void* unmanaged)
         {
             if (unmanaged != null)