Remove unnecessary trimming workarounds (#47241)

dotnet/linker#1981 has been fixed. We can now remove these workarounds in aspnetcore.

Author: eerhardt

src/Hosting/Hosting/src/GenericHost/GenericWebHostBuilder.cs

@@ -169,14 +169,12 @@ public IWebHostBuilder UseStartup([DynamicallyAccessedMembers(StartupLinkerOptio
         // UseStartup can be called multiple times. Only run the last one.
         _startupObject = startupType;
 
-        var state = new UseStartupState(startupType);
-
         _builder.ConfigureServices((context, services) =>
         {
             // Run this delegate if the startup type matches
-            if (object.ReferenceEquals(_startupObject, state.StartupType))
+            if (object.ReferenceEquals(_startupObject, startupType))
             {
-                UseStartup(state.StartupType, context, services);
+                UseStartup(startupType, context, services);
             }
         });
 

src/Hosting/Hosting/src/Internal/UseStartupState.cs

@@ -144,21 +144,19 @@ public static IWebHostBuilder UseStartup(this IWebHostBuilder hostBuilder, [Dyna
 
         hostBuilder.UseSetting(WebHostDefaults.ApplicationKey, startupAssemblyName);
 
-        var state = new UseStartupState(startupType);
-
         return hostBuilder
             .ConfigureServices(services =>
             {
-                if (typeof(IStartup).IsAssignableFrom(state.StartupType))
+                if (typeof(IStartup).IsAssignableFrom(startupType))
                 {
-                    services.AddSingleton(typeof(IStartup), state.StartupType);
+                    services.AddSingleton(typeof(IStartup), startupType);
                 }
                 else
                 {
                     services.AddSingleton(typeof(IStartup), sp =>
                     {
                         var hostingEnvironment = sp.GetRequiredService<IHostEnvironment>();
-                        return new ConventionBasedStartup(StartupLoader.LoadMethods(sp, state.StartupType, hostingEnvironment.EnvironmentName));
+                        return new ConventionBasedStartup(StartupLoader.LoadMethods(sp, startupType, hostingEnvironment.EnvironmentName));
                     });
                 }
             });

src/Hosting/Hosting/src/WebHostBuilderExtensions.cs

@@ -53,26 +53,13 @@ public void AddScheme(string name, Action<AuthenticationSchemeBuilder> configure
     /// <param name="displayName">The display name for the scheme.</param>
     public void AddScheme<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] THandler>(string name, string? displayName) where THandler : IAuthenticationHandler
     {
-        var state = new AddSchemeState(typeof(THandler));
         AddScheme(name, b =>
         {
             b.DisplayName = displayName;
-            b.HandlerType = state.HandlerType;
+            b.HandlerType = typeof(THandler);
         });
     }
 
-    // Workaround for linker bug: https://github.com/dotnet/linker/issues/1981
-    private readonly struct AddSchemeState
-    {
-        public AddSchemeState([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] Type handlerType)
-        {
-            HandlerType = handlerType;
-        }
-
-        [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]
-        public Type HandlerType { get; }
-    }
-
     /// <summary>
     /// Used as the fallback default scheme for all the other defaults.
     /// </summary>

src/Http/Authentication.Abstractions/src/AuthenticationOptions.cs

@@ -94,12 +94,8 @@ public static IApplicationBuilder UseMiddleware(
             throw new InvalidOperationException(Resources.FormatException_UseMiddlewareNoParameters(InvokeMethodName, InvokeAsyncMethodName, nameof(HttpContext)));
         }
 
-        var state = new InvokeMiddlewareState(middleware);
-
         return app.Use(next =>
         {
-            var middleware = state.Middleware;
-
             var ctorArgs = new object[args.Length + 1];
             ctorArgs[0] = next;
             Array.Copy(args, 0, ctorArgs, 1, args.Length);
@@ -268,16 +264,4 @@ private static object GetService(IServiceProvider sp, Type type, Type middleware
 
         return service;
     }
-
-    // Workaround for linker bug: https://github.com/dotnet/linker/issues/1981
-    private readonly struct InvokeMiddlewareState
-    {
-        public InvokeMiddlewareState([DynamicallyAccessedMembers(MiddlewareAccessibility)] Type middleware)
-        {
-            Middleware = middleware;
-        }
-
-        [DynamicallyAccessedMembers(MiddlewareAccessibility)]
-        public Type Middleware { get; }
-    }
 }

src/Http/Http.Abstractions/src/Extensions/UseMiddlewareExtensions.cs

@@ -73,10 +73,9 @@ public RateLimiterOptions AddPolicy<TPartitionKey>(string policyName, Func<HttpC
             throw new ArgumentException($"There already exists a policy with the name {policyName}.", nameof(policyName));
         }
 
-        var policyType = new PolicyTypeState(typeof(TPolicy));
         Func<IServiceProvider, DefaultRateLimiterPolicy> policyFunc = serviceProvider =>
         {
-            var instance = (IRateLimiterPolicy<TPartitionKey>)ActivatorUtilities.CreateInstance(serviceProvider, policyType.PolicyType);
+            var instance = (IRateLimiterPolicy<TPartitionKey>)ActivatorUtilities.CreateInstance(serviceProvider, typeof(TPolicy));
             return new DefaultRateLimiterPolicy(ConvertPartitioner<TPartitionKey>(policyName, instance.GetPartition), instance.OnRejected);
         };
 
@@ -116,16 +115,4 @@ internal static Func<HttpContext, RateLimitPartition<DefaultKeyType>> ConvertPar
             return new RateLimitPartition<DefaultKeyType>(partitionKey, static key => ((Func<TPartitionKey, RateLimiter>)key.Factory!)((TPartitionKey)key.Key!));
         };
     }
-
-    // Workaround for linker bug: https://github.com/dotnet/linker/issues/1981
-    private readonly struct PolicyTypeState
-    {
-        public PolicyTypeState([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] Type policyType)
-        {
-            PolicyType = policyType;
-        }
-
-        [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]
-        public Type PolicyType { get; }
-    }
 }

src/Middleware/RateLimiting/src/RateLimiterOptions.cs

@@ -31,12 +31,11 @@ public AuthenticationBuilder(IServiceCollection services)
         where TOptions : AuthenticationSchemeOptions, new()
         where THandler : class, IAuthenticationHandler
     {
-        var state = new AddSchemeHelperState(typeof(THandler));
         Services.Configure<AuthenticationOptions>(o =>
         {
             o.AddScheme(authenticationScheme, scheme =>
             {
-                scheme.HandlerType = state.HandlerType;
+                scheme.HandlerType = typeof(THandler);
                 scheme.DisplayName = displayName;
             });
         });
@@ -53,18 +52,6 @@ public AuthenticationBuilder(IServiceCollection services)
         return this;
     }
 
-    // Workaround for linker bug: https://github.com/dotnet/linker/issues/1981
-    private readonly struct AddSchemeHelperState
-    {
-        public AddSchemeHelperState([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] Type handlerType)
-        {
-            HandlerType = handlerType;
-        }
-
-        [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]
-        public Type HandlerType { get; }
-    }
-
     /// <summary>
     /// Adds a <see cref="AuthenticationScheme"/> which can be used by <see cref="IAuthenticationService"/>.
     /// </summary>