PR feedback

Author: marek-safar

src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml

@@ -18,8 +18,14 @@
     <type fullname="System.Threading.Tasks.Task" feature="System.Diagnostics.Debugger.IsSupported" featurevalue="false">
       <field name="s_asyncDebuggingEnabled" value="false" initialize="false" />
     </type>
-    <type fullname="System.Type" feature="System.Runtime.InteropServices.Marshal.IsComSupported" featurevalue="false">
+  </assembly>
+  <assembly fullname="System.Private.CoreLib" feature="System.Runtime.InteropServices.Marshal.IsComSupported" featurevalue="false">
+    <type fullname="System.Type" >
       <method signature="System.Boolean get_IsCOMObject()" body="stub" value="false" />
     </type>
+    <type fullname="System.Runtime.InteropServices.Marshal">
+      <method signature="System.Boolean IsComObject(System.Object)" body="stub" value="false" />
+      <method signature="System.Boolean IsTypeVisibleFromCom(System.Type)" body="stub" value="false" />
+    </type>
   </assembly>
 </linker>

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshal.NoCom.cs

@@ -195,9 +195,24 @@ public static object GetUniqueObjectForIUnknown(IntPtr unknown)
             throw new PlatformNotSupportedException(SR.PlatformNotSupported_ComInterop);
         }
 
-        public static bool IsComObject(object o) => false;
+        public static bool IsComObject(object o)
+        {
+            if (o is null)
+            {
+                throw new ArgumentNullException(nameof(o));
+            }
+
+            return false;
+        }
 
-        public static bool IsTypeVisibleFromCom(Type t) => false;
+        public static bool IsTypeVisibleFromCom(Type t)
+        {
+            if (t is null)
+            {
+                throw new ArgumentNullException(nameof(t));
+            }
+            return false;
+        }
 
         internal static bool IsComSupported => false;
 

src/mono/netcore/System.Private.CoreLib/src/System/RuntimeType.Mono.cs

@@ -2377,6 +2377,9 @@ public override Guid GUID
         {
             get
             {
+                if (!Marshal.IsComSupported)
+                    return Guid.Empty;
+
                 object[] att = GetCustomAttributes(typeof(System.Runtime.InteropServices.GuidAttribute), true);
                 if (att.Length == 0)
                     return Guid.Empty;