Trim regex from Grpc.AspNetCore

src/Grpc.AspNetCore.Server/GrpcServiceExtensions.cs

@@ -58,12 +58,14 @@ public static IGrpcServerBuilder AddGrpc(this IServiceCollection services)
     {
         ArgumentNullThrowHelper.ThrowIfNull(services);
 
-        services.AddRouting(options =>
-        {
-            // Unimplemented constraint is added to the route as an inline constraint to avoid RoutePatternFactory.Parse overload that includes parameter policies. That overload infers strings as regex constraints, which brings in
-            // the regex engine when publishing trimmed or AOT apps. This change reduces Native AOT gRPC server app size by about 1 MB.
-            AddParameterPolicy<GrpcUnimplementedConstraint>(options, GrpcServerConstants.GrpcUnimplementedConstraintPrefix);
-        });
+#if NET8_0_OR_GREATER
+        // Prefer AddRoutingCore when available.
+        // AddRoutingCore doesn't register a regex constraint and produces smaller result from trimming.
+        services.AddRoutingCore();
+        services.Configure<RouteOptions>(ConfigureRouting);
+#else
+        services.AddRouting(ConfigureRouting);
+#endif
         services.AddOptions();
         services.TryAddSingleton<GrpcMarkerService>();
         services.TryAddSingleton(typeof(ServerCallHandlerFactory<>));
@@ -78,6 +80,13 @@ public static IGrpcServerBuilder AddGrpc(this IServiceCollection services)
 
         return new GrpcServerBuilder(services);
 
+        static void ConfigureRouting(RouteOptions options)
+        {
+            // Unimplemented constraint is added to the route as an inline constraint to avoid RoutePatternFactory.Parse overload that includes parameter policies. That overload infers strings as regex constraints, which brings in
+            // the regex engine when publishing trimmed or AOT apps. This change reduces Native AOT gRPC server app size by about 1 MB.
+            AddParameterPolicy<GrpcUnimplementedConstraint>(options, GrpcServerConstants.GrpcUnimplementedConstraintPrefix);
+        }
+
         // This ensures the policy's constructors are preserved in .NET 6 with trimming. Remove when .NET 6 is no longer supported.
         static void AddParameterPolicy<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] T>(RouteOptions options, string name)
             where T : IParameterPolicy

testassets/LinkerTestsClient/LinkerTestsClient.csproj

@@ -5,6 +5,9 @@
     <OutputType>Exe</OutputType>
     <PublishTrimmed>true</PublishTrimmed>
     <PublishAot>$(AppPublishAot)</PublishAot>
+
+    <IlcGenerateMstatFile>$(GenerateAotDiaganostics)</IlcGenerateMstatFile>
+    <IlcGenerateDgmlFile>$(GenerateAotDiaganostics)</IlcGenerateDgmlFile>
   </PropertyGroup>
 
   <ItemGroup>

testassets/LinkerTestsClient/Program.cs

@@ -22,72 +22,65 @@
 using Microsoft.Extensions.DependencyInjection;
 using Unimplemented;
 
-namespace Client;
-
 // This app tests clients created directly from channel and clients created from factory.
 // Because of the vagaries of trimming, there is a small chance that testing both in the same app could
 // cause them to work when alone they might fail. Consider splitting into different client apps.
-public class Program
+
+try
 {
-    static async Task<int> Main(string[] args)
+    if (args.Length != 1 || !int.TryParse(args[0], out var port))
     {
-        try
-        {
-            if (args.Length != 1 || !int.TryParse(args[0], out var port))
-            {
-                throw new Exception("Port must be passed as an argument.");
-            }
+        throw new Exception("Port must be passed as an argument.");
+    }
 
-            var address = new Uri($"http://localhost:{port}");
+    var address = new Uri($"http://localhost:{port}");
 
-            // Basic channel
-            using var channel = GrpcChannel.ForAddress(address);
-            await CallGreeter(new Greeter.GreeterClient(channel));
-            await CallUnimplemented(new UnimplementedService.UnimplementedServiceClient(channel));
+    // Basic channel
+    using var channel = GrpcChannel.ForAddress(address);
+    await CallGreeter(new Greeter.GreeterClient(channel));
+    await CallUnimplemented(new UnimplementedService.UnimplementedServiceClient(channel));
 
-            // Client factory
-            var services = new ServiceCollection();
-            services.AddGrpcClient<Greeter.GreeterClient>(op =>
-            {
-                op.Address = address;
-            });
-            services.AddGrpcClient<UnimplementedService.UnimplementedServiceClient>(op =>
-            {
-                op.Address = address;
-            });
-            var serviceProvider = services.BuildServiceProvider();
-
-            await CallGreeter(serviceProvider.GetRequiredService<Greeter.GreeterClient>());
-            await CallUnimplemented(serviceProvider.GetRequiredService<UnimplementedService.UnimplementedServiceClient>());
+    // Client factory
+    var services = new ServiceCollection();
+    services.AddGrpcClient<Greeter.GreeterClient>(op =>
+    {
+        op.Address = address;
+    });
+    services.AddGrpcClient<UnimplementedService.UnimplementedServiceClient>(op =>
+    {
+        op.Address = address;
+    });
+    var serviceProvider = services.BuildServiceProvider();
 
-            Console.WriteLine("Shutting down");
-            return 0;
-        }
-        catch (Exception ex)
-        {
-            Console.Error.WriteLine(ex.ToString());
-            return 1;
-        }
-    }
+    await CallGreeter(serviceProvider.GetRequiredService<Greeter.GreeterClient>());
+    await CallUnimplemented(serviceProvider.GetRequiredService<UnimplementedService.UnimplementedServiceClient>());
 
-    private static async Task CallGreeter(Greeter.GreeterClient client)
+    Console.WriteLine("Shutting down");
+    return 0;
+}
+catch (Exception ex)
+{
+    Console.Error.WriteLine(ex.ToString());
+    return 1;
+}
+
+static async Task CallGreeter(Greeter.GreeterClient client)
+{
+    var reply = await client.SayHelloAsync(new HelloRequest { Name = "GreeterClient" });
+    Console.WriteLine("Greeting: " + reply.Message);
+}
+
+static async Task CallUnimplemented(UnimplementedService.UnimplementedServiceClient client)
+{
+    var reply = client.DuplexData();
+
+    try
     {
-        var reply = await client.SayHelloAsync(new HelloRequest { Name = "GreeterClient" });
-        Console.WriteLine("Greeting: " + reply.Message);
+        await reply.ResponseStream.MoveNext();
+        throw new Exception("Expected error status.");
     }
-
-    private static async Task CallUnimplemented(UnimplementedService.UnimplementedServiceClient client)
+    catch (RpcException ex) when (ex.StatusCode == StatusCode.Unimplemented)
     {
-        var reply = client.DuplexData();
-
-        try
-        {
-            await reply.ResponseStream.MoveNext();
-            throw new Exception("Expected error status.");
-        }
-        catch (RpcException ex) when (ex.StatusCode == StatusCode.Unimplemented)
-        {
-            Console.WriteLine("Unimplemented status correctly returned.");
-        }
+        Console.WriteLine("Unimplemented status correctly returned.");
     }
 }

testassets/LinkerTestsWebsite/LinkerTestsWebsite.csproj

@@ -11,6 +11,9 @@
     -->
     <TrimMode>full</TrimMode>
     <TrimmerSingleWarn>false</TrimmerSingleWarn>
+
+    <IlcGenerateMstatFile>$(GenerateAotDiaganostics)</IlcGenerateMstatFile>
+    <IlcGenerateDgmlFile>$(GenerateAotDiaganostics)</IlcGenerateDgmlFile>
   </PropertyGroup>
 
   <ItemGroup>

testassets/LinkerTestsWebsite/Program.cs

@@ -17,31 +17,23 @@
 #endregion
 
 using Microsoft.AspNetCore.Server.Kestrel.Core;
+using Server;
 
-namespace Server;
-
-public class Program
+var builder = WebApplication.CreateSlimBuilder(args);
+builder.Logging.SetMinimumLevel(LogLevel.Trace);
+builder.WebHost.ConfigureKestrel(options =>
 {
-    public static void Main(string[] args)
+    options.ListenAnyIP(0, listenOptions =>
     {
-        CreateHostBuilder(args).Build().Run();
-    }
-
-    public static IHostBuilder CreateHostBuilder(string[] args) =>
-        Host.CreateDefaultBuilder(args)
-            .ConfigureWebHostDefaults(webBuilder =>
-            {
-                webBuilder.UseStartup<Startup>();
-                webBuilder.ConfigureKestrel(options =>
-                {
-                    options.ListenAnyIP(0, listenOptions =>
-                    {
-                        listenOptions.Protocols = HttpProtocols.Http2;
-                    });
-                });
-            })
-            .ConfigureLogging(logging =>
-            {
-                logging.SetMinimumLevel(LogLevel.Trace);
-            });
-}
+        listenOptions.Protocols = HttpProtocols.Http2;
+    });
+});
+
+builder.Services.AddGrpc();
+
+var app = builder.Build();
+
+app.MapGrpcService<GreeterService>();
+
+app.Lifetime.ApplicationStarted.Register(() => Console.WriteLine("Application started. Press Ctrl+C to shut down."));
+app.Run();