From 225addf752d4a1690a3a83bdcaa8151886647373 Mon Sep 17 00:00:00 2001
From: Marek Safar <marek.safar@gmail.com>
Date: Thu, 24 Dec 2020 09:22:54 +0100
Subject: [PATCH] Remove ICustomMarshaler from linker descriptor linker can
 keep the type (#46333)

* Remove ICustomMarshaler from linker descriptor linker can keep the type
conditionally

* Add dependency link to runtime infrastructure code
---
 .../src/System/Runtime/InteropServices/ICustomMarshaler.cs           | 4 ++++
 .../netcore/System.Private.CoreLib/src/ILLink/ILLink.Descriptors.xml | 5 -----
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/ICustomMarshaler.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/ICustomMarshaler.cs
index 9b1c0b4..3fc2c73 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/ICustomMarshaler.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/ICustomMarshaler.cs
@@ -6,6 +6,10 @@ namespace System.Runtime.InteropServices
     // This the base interface that must be implemented by all custom marshalers.
     public interface ICustomMarshaler
     {
+#if MONO
+        // ILLinker marks all methods of this type equaly so the attribute can be on any of them
+        [System.Diagnostics.CodeAnalysis.DynamicDependency(nameof(Marshal.GetCustomMarshalerInstance), typeof(Marshal))]
+#endif
         object MarshalNativeToManaged(IntPtr pNativeData);
 
         IntPtr MarshalManagedToNative(object ManagedObj);
diff --git a/src/mono/netcore/System.Private.CoreLib/src/ILLink/ILLink.Descriptors.xml b/src/mono/netcore/System.Private.CoreLib/src/ILLink/ILLink.Descriptors.xml
index b583af7..cf4742d 100644
--- a/src/mono/netcore/System.Private.CoreLib/src/ILLink/ILLink.Descriptors.xml
+++ b/src/mono/netcore/System.Private.CoreLib/src/ILLink/ILLink.Descriptors.xml
@@ -569,13 +569,8 @@
 			<method signature="System.Void .ctor(System.Object)" />
 		</type>
 
-		<!-- marshal.c: emit_marshal_custom (DISABLE_JIT is not defined for the AOT compiler, only the ARM runtimes) -->
-		<type fullname="System.Runtime.InteropServices.ICustomMarshaler" />
-
 		<!-- domain.c: mono_defaults.marshal_class -->
 		<type fullname="System.Runtime.InteropServices.Marshal" preserve="fields" >
-			<!-- marshal-ilgen.c: emit_marshal_custom_get_instance -->
-			<method name="GetCustomMarshalerInstance" />
 			<!-- marshal.c (mono_marshal_get_struct_to_ptr) -->
 			<method name="StructureToPtr" />
 		</type>
-- 
2.7.4