Runtime: System.Security.VerificationException (type argument violates the constraint of type parameter) when running code on net 5.0

Created on 4 Dec 2020 · 4Comments · Source: dotnet/runtime

Description

Hi, we have encountered strange exception after one of ours project's target framework has been upgraded from netcoreapp3.1 to net5.0.

This is the exception message:

Unhandled exception. System.Security.VerificationException: Method ConsoleApp1.ComponentRegistry`1[ConsoleApp1.NamedObjectComponent`1[TNamedObject]].Register: type argument 'TComponentA' violates the constraint of type parameter 'TComponent'.
   at ConsoleApp1.SingleTypeNamedObjectContainer`1.Register[TComponentA]()
   at ConsoleApp1.NamedObjectContainer.Register[TNamedObject,TComponent]() in /Users/gureev/RiderProjects/ConsoleApp1/ConsoleApp1/Program.cs:line 87
   at ConsoleApp1.Program.Main(String[] args) in /Users/gureev/RiderProjects/ConsoleApp1/ConsoleApp1/Program.cs:line 108

I made simple console app to reproduce it:

    class Program
    {
        public abstract class NamedObject { }

        public class FooNamedObject : NamedObject { }

        public abstract class NamedObjectComponent { }

        public abstract class NamedObjectComponent<TNamedObject> : NamedObjectComponent where TNamedObject : NamedObject { }

        public class FooNamedObjectComponent : NamedObjectComponent<FooNamedObject> { }

        public abstract class SingleTypeNamedObjectContainer
        {
            internal SingleTypeNamedObjectContainer() { }

            internal abstract Type NamedObjectType { get; }
        }

        public class SingleTypeNamedObjectContainer<TNamedObject> : SingleTypeNamedObjectContainer
            where TNamedObject : NamedObject
        {
            private readonly ComponentRegistry<NamedObjectComponent<TNamedObject>> components =
                new ComponentRegistry<NamedObjectComponent<TNamedObject>>();

            internal override Type NamedObjectType => typeof(TNamedObject);

            public void Register<TComponentA>()
                where TComponentA : NamedObjectComponent<TNamedObject>, new()
            {
                components.Register<TComponentA>();
            }
        }

        public class ComponentRegistry<TBaseComponent> where TBaseComponent : class
        {
            private readonly HashSet<Type> componentTypes = new HashSet<Type>();

            private readonly Dictionary<Type, Func<TBaseComponent>> componentFactories =
                new Dictionary<Type, Func<TBaseComponent>>();

            public void Register<TComponent>()
                where TComponent : class, TBaseComponent, new()
            {
                Register(() => new TComponent());
            }

            public void Register<TComponent>(Func<TComponent> componentFactory)
                where TComponent : class, TBaseComponent
            {
                componentTypes.Add(typeof(TComponent));
                componentFactories.Add(typeof(TComponent), componentFactory);
            }
        }

        public class NamedObjectContainer
        {
            private readonly Dictionary<Type, SingleTypeNamedObjectContainer> subcontainersByNamedObjectType =
                new Dictionary<Type, SingleTypeNamedObjectContainer>();

            private readonly Dictionary<Type, SingleTypeNamedObjectContainer> subcontainersByRegisteredType =
                new Dictionary<Type, SingleTypeNamedObjectContainer>();

            public SingleTypeNamedObjectContainer<TNamedObject> RegisterNamedObjectType<TNamedObject>()
                where TNamedObject : NamedObject
            {
                return RegisterSubcontainer(new SingleTypeNamedObjectContainer<TNamedObject>());
            }

            public TSubcontainer RegisterSubcontainer<TSubcontainer>(TSubcontainer subcontainer)
                where TSubcontainer : SingleTypeNamedObjectContainer
            {
                subcontainersByNamedObjectType.Add(subcontainer.NamedObjectType, subcontainer);
                subcontainersByRegisteredType.Add(typeof(TSubcontainer), subcontainer);
                return subcontainer;
            }

            internal void Register<TNamedObject, TComponent>()
                where TNamedObject : NamedObject
                where TComponent : NamedObjectComponent<TNamedObject>, new()
            {
                GetSubcontainerFor<TNamedObject>().Register<TComponent>();
            }

            public SingleTypeNamedObjectContainer<TNamedObject> GetSubcontainerFor<TNamedObject>()
                where TNamedObject : NamedObject
            {
                return (SingleTypeNamedObjectContainer<TNamedObject>)GetSubcontainerFor(typeof(TNamedObject));
            }

            public SingleTypeNamedObjectContainer GetSubcontainerFor(Type baseNamedObjectType)
            {
                return subcontainersByNamedObjectType[baseNamedObjectType];
            }
        }

        static void Main(string[] args)
        {
            var contaner = new NamedObjectContainer();
            contaner.RegisterNamedObjectType<FooNamedObject>();
            contaner.Register<FooNamedObject, FooNamedObjectComponent>();
        }       
    }

If you run this code with target netcoreapp3.1 - it works.
But if you run with target netcoreapp5.0 - exception throws.

Configuration

Dotnet sdk 5.0.100
OS: MacOS Catalina (x64), Windows 10 1903 (x64)

Regression?

Yes, works on 3.1.

area-TypeSystem-coreclr untriaged

Source

GureevLeonid

👍9 👀1

Most helpful comment

Let me run the repro locally and see where the exception stems from in the native runtime.

janvorli on 4 Dec 2020

👍3

All 4 comments

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Issue Details