TypeBuilder.CreateType doesn't work on Windows in a trimmed app due to BuiltInComInterop being disabled

[eerhardt]

Description

When trimming an app that uses Ref.Emit to generate a Type, it fails by default on Windows due to BuiltInComInterop being disabled.

Using a recent .NET 6 SDK, dotnet publish the following app:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
    <PublishTrimmed>true</PublishTrimmed>
  </PropertyGroup>
</Project>

using System;
using System.Reflection;
using System.Reflection.Emit;

AssemblyBuilder assembly = AssemblyBuilder.DefineDynamicAssembly(new AssemblyName("GeneratedAssembly"), AssemblyBuilderAccess.Run);
ModuleBuilder module = assembly.DefineDynamicModule("GeneratedModule");
TypeBuilder genericType = module.DefineType("GeneratedType");
genericType.DefineField("_int", typeof(int), FieldAttributes.Private);
genericType.DefineProperty("Prop", PropertyAttributes.None, typeof(string), null);

Type generatedType = genericType.CreateType();
Console.WriteLine(generatedType);

❯ .\bin\Debug\net6.0\win-x64\publish\HelloWorld.exe
Unhandled exception. System.TypeLoadException: Could not load type 'System.Runtime.InteropServices.DispatchWrapper' from assembly 'System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e'.
   at System.Reflection.Emit.TypeBuilder.SetMethodIL(QCallModule , Int32 , Boolean , Byte[] , Int32 , Byte[] , Int32 , Int32 , ExceptionHandler[] , Int32 , Int32[] , Int32 )
   at System.Reflection.Emit.TypeBuilder.CreateTypeNoLock() in System.Private.CoreLib.dll:token 0x60025e7+0x37f
   at System.Reflection.Emit.TypeBuilder.CreateType() in System.Private.CoreLib.dll:token 0x60025e6+0x11
   at <Program>$.<Main>$(String[] ) in C:\DotNetTest\HelloWorld\Program.cs:line 11

Configuration

• Which version of .NET is the code running on? .NET 6.0.0-preview5+
• What OS and version, and what distro if applicable? Windows
• What is the architecture (x64, x86, ARM, ARM64)? x64
• Do you know whether it is specific to that configuration? yes

Regression?

Yes, this worked before 6.0.0-preview5 because BuiltInComInterop wasn't disabled by default. We disable BuiltInComInterop by default starting in 6.0.0-preview5.

cc @LakshanF @agocke @vitek-karas @sbomer

[ghost]

Tagging subscribers to 'linkable-framework': @eerhardt, @vitek-karas, @LakshanF, @sbomer, @joperezr
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Issue Details

---

Description

When trimming an app that uses Ref.Emit to generate a Type, it fails by default on Windows due to BuiltInComInterop being disabled.

Using a recent .NET 6 SDK, dotnet publish the following app:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
    <PublishTrimmed>true</PublishTrimmed>
  </PropertyGroup>
</Project>

using System;
using System.Reflection;
using System.Reflection.Emit;

AssemblyBuilder assembly = AssemblyBuilder.DefineDynamicAssembly(new AssemblyName("GeneratedAssembly"), AssemblyBuilderAccess.Run);
ModuleBuilder module = assembly.DefineDynamicModule("GeneratedModule");
TypeBuilder genericType = module.DefineType("GeneratedType");
genericType.DefineField("_int", typeof(int), FieldAttributes.Private);
genericType.DefineProperty("Prop", PropertyAttributes.None, typeof(string), null);

Type generatedType = genericType.CreateType();
Console.WriteLine(generatedType);

❯ .\bin\Debug\net6.0\win-x64\publish\HelloWorld.exe
Unhandled exception. System.TypeLoadException: Could not load type 'System.Runtime.InteropServices.DispatchWrapper' from assembly 'System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e'.
   at System.Reflection.Emit.TypeBuilder.SetMethodIL(QCallModule , Int32 , Boolean , Byte[] , Int32 , Byte[] , Int32 , Int32 , ExceptionHandler[] , Int32 , Int32[] , Int32 )
   at System.Reflection.Emit.TypeBuilder.CreateTypeNoLock() in System.Private.CoreLib.dll:token 0x60025e7+0x37f
   at System.Reflection.Emit.TypeBuilder.CreateType() in System.Private.CoreLib.dll:token 0x60025e6+0x11
   at <Program>$.<Main>$(String[] ) in C:\DotNetTest\HelloWorld\Program.cs:line 11

Configuration

• Which version of .NET is the code running on? .NET 6.0.0-preview5+
• What OS and version, and what distro if applicable? Windows
• What is the architecture (x64, x86, ARM, ARM64)? x64
• Do you know whether it is specific to that configuration? yes

Regression?

Yes, this worked before 6.0.0-preview5 because BuiltInComInterop wasn't disabled by default. We disable BuiltInComInterop by default starting in 6.0.0-preview5.

cc @LakshanF @agocke @vitek-karas @sbomer

Author:	eerhardt
Assignees:	LakshanF
Labels:	area-Interop-coreclr, linkable-framework
Milestone:	6.0.0

[LakshanF]

It seems like this is failing when preparing the PInvoke call, SetMethodIL. Specifically trying to marshal some of the array parameters as the below call stack shows. OleVariant::GetVarTypeForTypeHandle has a check for DispatchWrapper under FEATURE_COMINTEROP. Non-Windows platforms bypass these checks to return VT_UNKNOWN that likely makes this scenario work in those platforms.

cc @elinor-fung, @jkoritzinsky

06 000000e0`77d7ce00 00007ffb`7c1c7e00     coreclr!ClassLoader::LoadTypeHandleThrowIfFailed+0xf3c3d [D:\workspace\_work\1\s\src\coreclr\vm\clsload.cpp @ 490] 
07 000000e0`77d7ce40 00007ffb`7c1c7d7f     coreclr!ClassLoader::LoadTypeByNameThrowing+0x68 [D:\workspace\_work\1\s\src\coreclr\vm\clsload.cpp @ 435] 
08 000000e0`77d7ced0 00007ffb`7c2cda9f     coreclr!CoreLibBinder::LookupClassLocal+0x47 [D:\workspace\_work\1\s\src\coreclr\vm\binder.cpp @ 73] 
09 (Inline Function) --------`--------     coreclr!CoreLibBinder::GetClass+0x1f [D:\workspace\_work\1\s\src\coreclr\vm\binder.h @ 354] 
0a (Inline Function) --------`--------     coreclr!CoreLibBinder::IsClass+0xc50f1 [D:\workspace\_work\1\s\src\coreclr\vm\binder.h @ 157] 
0b 000000e0`77d7cf20 00007ffb`7c2088be     coreclr!OleVariant::GetVarTypeForTypeHandle+0xc51c3 [D:\workspace\_work\1\s\src\coreclr\vm\olevariant.cpp @ 332]
0c 000000e0`77d7cf70 00007ffb`7c241bbe     coreclr!ArrayMarshalInfo::InitElementInfo+0x1d6 [D:\workspace\_work\1\s\src\coreclr\vm\mlinfo.cpp @ 3864] 
0d (Inline Function) --------`--------     coreclr!ArrayMarshalInfo::IsValid+0x17 [D:\workspace\_work\1\s\src\coreclr\vm\mlinfo.h @ 634] 
0e 000000e0`77d7cfd0 00007ffb`7c162dba     coreclr!MarshalInfo::HandleArrayElemType+0xba [D:\workspace\_work\1\s\src\coreclr\vm\mlinfo.cpp @ 2540] 
0f 000000e0`77d7d050 00007ffb`7c163ffe     coreclr!MarshalInfo::MarshalInfo+0x996 [D:\workspace\_work\1\s\src\coreclr\vm\mlinfo.cpp @ 2288] 
10 000000e0`77d7d300 00007ffb`7c169696     coreclr!CreateNDirectStubWorker+0x252 [D:\workspace\_work\1\s\src\coreclr\vm\dllimport.cpp @ 3757] 
11 000000e0`77d7d500 00007ffb`7c16929e     coreclr!`anonymous namespace'::CreateInteropILStub+0x306 [D:\workspace\_work\1\s\src\coreclr\vm\dllimport.cpp @ 5107] 
12 000000e0`77d7db30 00007ffb`7c168f7b     coreclr!NDirect::CreateCLRToNativeILStub+0x162 [D:\workspace\_work\1\s\src\coreclr\vm\dllimport.cpp @ 5228] 
13 000000e0`77d7dc20 00007ffb`7c168d43     coreclr!NDirect::CreateCLRToNativeILStub+0x9f [D:\workspace\_work\1\s\src\coreclr\vm\dllimport.cpp @ 5459] 
14 000000e0`77d7dcd0 00007ffb`7c168a3d     coreclr!NDirect::GetILStubMethodDesc+0x3b [D:\workspace\_work\1\s\src\coreclr\vm\dllimport.cpp @ 5479] 
15 000000e0`77d7dd00 00007ffb`7c168db6     coreclr!NDirect::GetStubForILStub+0x41 [D:\workspace\_work\1\s\src\coreclr\vm\dllimport.cpp @ 5675] 
16 000000e0`77d7dd50 00007ffb`7c12e9da     coreclr!GetStubForInteropMethod+0x5e [D:\workspace\_work\1\s\src\coreclr\vm\dllimport.cpp @ 5868] 
17 000000e0`77d7dd90 00007ffb`7c12e4eb     coreclr!MethodDesc::DoPrestub+0x3ba [D:\workspace\_work\1\s\src\coreclr\vm\prestub.cpp @ 2266] 
18 000000e0`77d7dec0 00007ffb`7c252055     coreclr!PreStubWorker+0x21b [D:\workspace\_work\1\s\src\coreclr\vm\prestub.cpp @ 2033] 
19 000000e0`77d7e050 00007ffb`1c67806e     coreclr!ThePreStub+0x55
1a 000000e0`77d7e100 00007ffb`1c677604     System_Private_CoreLib!System.Reflection.Emit.TypeBuilder.CreateTypeNoLock()+0x5ee

[jkoritzinsky]

I think we should wrap that block in a check for if built-in COM is enabled.

[elinor-fung]

Yeah. Probably also worth doing a search for all those wrapper classes / other similar checks in the runtime and seeing if they are already blocked or they need to be blocked.