Add the ability to remove COM support using ILLinker

Fixes dotnet#36659
marek-safar · Oct 16, 2020 · a796341 · a796341
1 parent b6af738
commit a796341
Show file tree

Hide file tree

Showing 5 changed files with 40 additions and 17 deletions.
diff --git a/src/coreclr/src/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshal.CoreCLR.cs b/src/coreclr/src/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshal.CoreCLR.cs
@@ -445,6 +445,8 @@ public static IntPtr CreateAggregatedObject<T>(IntPtr pOuter, T o) where T : not
         [MethodImpl(MethodImplOptions.InternalCall)]
         public static extern bool IsComObject(object o);
 
+        internal static bool IsComSupported => true;
+
         /// <summary>
         /// Release the COM component and if the reference hits 0 zombie this object.
         /// Further usage of this Object might throw an exception

diff --git a/src/libraries/Microsoft.CSharp/src/ILLink/ILLinkTrim.xml b/src/libraries/Microsoft.CSharp/src/ILLink/ILLinkTrim.xml
@@ -1,5 +1,5 @@
 <linker>
-  <assembly fullname="Microsoft.CSharp">
+  <assembly fullname="Microsoft.CSharp" feature="System.Runtime.InteropServices.Marshal.IsComSupported" featurevalue="true" featuredefault="true">
     <!-- Required for COM event dispatch -->
     <type fullname="System.Runtime.InteropServices.ComEventsSink"/>
   </assembly>

diff --git a/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.LinkAttributes.Shared.xml b/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.LinkAttributes.Shared.xml
@@ -51,4 +51,35 @@
       <attribute internal="RemoveAttributeInstances" />
     </type>
   </assembly>
+
+  <!-- COM specific attributes -->
+  <assembly fullname="System.Private.CoreLib" feature="System.Runtime.InteropServices.Marshal.IsComSupported" featurevalue="false">
+    <type fullname="System.MTAThreadAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+    <type fullname="System.STAThreadAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+    <type fullname="System.Runtime.InteropServices.ClassInterfaceAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+    <type fullname="System.Runtime.InteropServices.CoClassAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+    <type fullname="System.Runtime.InteropServices.ComDefaultInterfaceAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+    <type fullname="System.Runtime.InteropServices.ComImportAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+    <type fullname="System.Runtime.InteropServices.ComVisibleAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+    <type fullname="System.Runtime.InteropServices.GuidAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+    <type fullname="System.Runtime.InteropServices.ProgIdAttribute">
+      <attribute internal="RemoveAttributeInstances" />
+    </type>
+  </assembly>
 </linker>
diff --git a/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml b/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml
@@ -18,5 +18,8 @@
     <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">
+      <method signature="System.Boolean get_IsCOMObject()" body="stub" value="false" />
+    </type>
   </assembly>
 </linker>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshal.NoCom.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshal.NoCom.cs
@@ -195,24 +195,11 @@ public static object GetUniqueObjectForIUnknown(IntPtr unknown)
             throw new PlatformNotSupportedException(SR.PlatformNotSupported_ComInterop);
         }
 
-        public static bool IsComObject(object o)
-        {
-            if (o is null)
-            {
-                throw new ArgumentNullException(nameof(o));
-            }
+        public static bool IsComObject(object o) => false;
 
-            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;
 
         [SupportedOSPlatform("windows")]
         public static int QueryInterface(IntPtr pUnk, ref Guid iid, out IntPtr ppv)