[runtime] Store assemblies' MVID in the generated static registrar code.

runtime/xamarin/runtime.h

@@ -56,8 +56,8 @@ typedef struct {
 } MTProperty;
 
 // This structure completely describes everything required to resolve a metadata token
-typedef struct MTFullTokenReference {
-	const char *assembly_name; /* the name of the assembly */
+typedef struct __attribute__((packed)) {
+	uint32_t assembly_index; /* index into the 'assemblies' array in the registration map */
 	uint32_t module_token;
 	uint32_t token;
 } MTFullTokenReference;
@@ -99,10 +99,15 @@ typedef struct __attribute__((packed)) {
 	const __unsafe_unretained Protocol * const * protocols; // the corresponding native protocols
 } MTProtocolMap;
 
+typedef struct __attribute__((packed)) {
+	const char *name;
+	const char *mvid;
+} MTAssembly;
+
 struct MTRegistrationMap;
 
 struct MTRegistrationMap {
-	const char **assembly;
+	const MTAssembly *assemblies;
 	MTClassMap *map;
 	const MTFullTokenReference *full_token_references;
 	// There are some managed types that are not registered because their ObjC

src/ObjCRuntime/Class.cs

@@ -10,6 +10,7 @@
 #nullable enable
 
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
@@ -19,6 +20,10 @@
 using Registrar;
 #endif
 
+#if !COREBUILD
+using Xamarin.Bundler;
+#endif
+
 #if !NET
 using NativeHandle = System.IntPtr;
 #endif
@@ -56,8 +61,8 @@ internal unsafe static void Initialize (Runtime.InitializationOptions* options)
 
 
 			for (int i = 0; i < map->assembly_count; i++) {
-				var ptr = Marshal.ReadIntPtr (map->assembly, i * IntPtr.Size);
-				Runtime.Registrar.SetAssemblyRegistered (Marshal.PtrToStringAuto (ptr));
+				var assembly = map->assemblies [i];
+				Runtime.Registrar.SetAssemblyRegistered (Marshal.PtrToStringAuto (assembly.name));
 			}
 		}
 
@@ -292,27 +297,27 @@ unsafe static bool CompareTokenReference (string asm_name, int mod_token, int ty
 			if ((token_reference & 0x1) == 0x1) {
 				// full token reference
 				var idx = (int) (token_reference >> 1);
-				var entry = map->full_token_references + (IntPtr.Size + 8) * idx;
+				var entry = map->full_token_references [idx];
 				// first compare what's most likely to fail (the type's metadata token)
-				var token = (uint) Marshal.ReadInt32 (entry + IntPtr.Size + 4);
+				var token = entry.token;
 				type_token |= 0x02000000 /* TypeDef - the token type is explicit in the full token reference, but not present in the type_token argument, so we have to add it before comparing */;
 				if (type_token != token)
 					return false;
 
 				// then the module token
-				var module_token = (uint) Marshal.ReadInt32 (entry + IntPtr.Size);
+				var module_token = entry.module_token;
 				if (mod_token != module_token)
 					return false;
 
 				// leave the assembly name for the end, since it's the most expensive comparison (string comparison)
-				assembly_name = Marshal.ReadIntPtr (entry);
+				assembly_name = map->assemblies [entry.assembly_index].name;
 			} else {
 				// packed token reference
 				if (token_reference >> 8 != type_token)
 					return false;
 
 				var assembly_index = (token_reference >> 1) & 0x7F;
-				assembly_name = Marshal.ReadIntPtr (map->assembly, (int) assembly_index * IntPtr.Size);
+				assembly_name = map->assemblies [(int) assembly_index].name;
 			}
 
 			return Runtime.StringEquals (assembly_name, asm_name);
@@ -380,10 +385,11 @@ static unsafe int FindMapIndex (Runtime.MTClassMap *array, int lo, int hi, IntPt
 		internal unsafe static MemberInfo? ResolveFullTokenReference (uint token_reference)
 		{
 			// sizeof (MTFullTokenReference) = IntPtr.Size + 4 + 4
-			var entry = Runtime.options->RegistrationMap->full_token_references + (IntPtr.Size + 8) * (int) (token_reference >> 1);
-			var assembly_name = Marshal.ReadIntPtr (entry);
-			var module_token = (uint) Marshal.ReadInt32 (entry + IntPtr.Size);
-			var token = (uint) Marshal.ReadInt32 (entry + IntPtr.Size + 4);
+			var idx = (int) (token_reference >> 1);
+			var entry = Runtime.options->RegistrationMap->full_token_references [idx];
+			var assembly_name = Runtime.options->RegistrationMap->assemblies [entry.assembly_index].name;
+			var module_token = entry.module_token;
+			var token = entry.token;
 
 #if LOG_TYPELOAD
 			Console.WriteLine ($"ResolveFullTokenReference (0x{token_reference:X}) assembly name: {assembly_name} module token: 0x{module_token:X} token: 0x{token:X}.");
@@ -430,7 +436,7 @@ static unsafe int FindMapIndex (Runtime.MTClassMap *array, int lo, int hi, IntPt
 			Console.WriteLine ($"ResolveTokenReference (0x{token_reference:X}) assembly index: {assembly_index} token: 0x{token:X}.");
 #endif
 
-			var assembly_name = Marshal.ReadIntPtr (map->assembly, (int) assembly_index * IntPtr.Size);
+			var assembly_name = map->assemblies [(int) assembly_index].name;
 			var assembly = ResolveAssembly (assembly_name);
 			var module = ResolveModule (assembly, 0x1);
 
@@ -474,20 +480,80 @@ static Module ResolveModule (Assembly assembly, uint token)
 			throw ErrorHelper.CreateError (8020, $"Could not find the module with MetadataToken 0x{token:X} in the assembly {assembly}.");
 		}
 
+// Restrict this code to desktop for now, which is where most of the problems with outdated generated static registrar code occur.
+#if __MACOS__ || __MACCATALYST__
+		static bool? verify_static_registrar_code;
+		static object? verification_lock;
+		static Dictionary<IntPtr, object?>? verified_assemblies; // Use Dictionary instead of HashSet to avoid pulling in System.Core.dll.
+		unsafe static void VerifyStaticRegistrarCode (IntPtr assembly_name, Assembly assembly)
+		{
+			if (verify_static_registrar_code is null) {
+				verify_static_registrar_code = !string.IsNullOrEmpty (Environment.GetEnvironmentVariable ("XAMARIN_VALIDATE_STATIC_REGISTRAR_CODE"));
+				verification_lock = new object ();
+			}
+			if (verify_static_registrar_code != true)
+				return;
+
+			lock (verification_lock!) {
+				if (verified_assemblies is null) {
+					verified_assemblies = new Dictionary<IntPtr, object?> (Runtime.IntPtrEqualityComparer);
+				} else if (verified_assemblies.ContainsKey (assembly_name)) {
+					return;
+				}
+				verified_assemblies [assembly_name] = null;
+			}
+
+			var map = Runtime.options->RegistrationMap;
+			if (map is null)
+				return;
+
+			for (var i = 0; i < map->assembly_count; i++) {
+				var entry = map->assemblies [i];
+				var name = Marshal.PtrToStringAuto (entry.name)!;
+				if (!Runtime.StringEquals (assembly_name, name))
+					continue;
+				try {
+					var mvid = Marshal.PtrToStringAuto (entry.mvid)!;
+					var runtime_mvid = assembly.ManifestModule.ModuleVersionId;
+					var registered_mvid = Guid.Parse (mvid);
+					if (registered_mvid == runtime_mvid)
+						continue;
+					throw ErrorHelper.CreateError (8044, Errors.MX8044 /* The assembly {0} has been modified since the app was built, invalidating the generated static registrar code. The MVID for the loaded assembly is {1}, while the MVID for the assembly the generated static registrar code corresponds to is {2}. */, name, runtime_mvid, registered_mvid);
+				} catch (Exception e) {
+					throw ErrorHelper.CreateError (8043, e, Errors.MX8043 /* An exception occurred while validating the static registrar code for {0}: {1} */, name, e.Message);
+				}
+			}
+		}
+#endif // __MACOS__ || __MACCATALYST__
+
 		static Assembly ResolveAssembly (IntPtr assembly_name)
+		{
+			if (TryResolveAssembly (assembly_name, out var asm)) {
+#if __MACOS__ || __MACCATALYST__
+				VerifyStaticRegistrarCode (assembly_name, asm);
+#endif
+				return asm;
+			}
+
+			throw ErrorHelper.CreateError (8019, $"Could not find the assembly {Marshal.PtrToStringAuto (assembly_name)} in the loaded assemblies.");
+		}
+
+		static bool TryResolveAssembly (IntPtr assembly_name, [NotNullWhen (true)] out Assembly? assembly)
 		{
 			// Find the assembly. We've already loaded all the assemblies that contain registered types, so just look at those assemblies.
 			foreach (var asm in AppDomain.CurrentDomain.GetAssemblies ()) {
 				if (!Runtime.StringEquals (assembly_name, asm.GetName ().Name))
 					continue;
 
 #if LOG_TYPELOAD
-				Console.WriteLine ($"ResolveAssembly (0x{assembly_name:X}): {asm.FullName}.");
+				Console.WriteLine ($"TryResolveAssembly (0x{assembly_name:X}): {asm.FullName}.");
 #endif
-				return asm;
+				assembly = asm;
+				return true;
 			}
 
-			throw ErrorHelper.CreateError (8019, $"Could not find the assembly {Marshal.PtrToStringAuto (assembly_name)} in the loaded assemblies.");
+			assembly = null;
+			return false;
 		}
 
 		internal unsafe static uint GetTokenReference (Type type, bool throw_exception = true)
@@ -514,7 +580,7 @@ internal unsafe static uint GetTokenReference (Type type, bool throw_exception =
 			// Find the assembly index in our list of registered assemblies.
 			int assembly_index = -1;
 			for (int i = 0; i < map->assembly_count; i++) {
-				var name_ptr = Marshal.ReadIntPtr (map->assembly, (int) i * IntPtr.Size);
+				var name_ptr = map->assemblies [(int) i].name;
 				if (Runtime.StringEquals (name_ptr, asm_name)) {
 					assembly_index = i;
 					break;
@@ -542,15 +608,16 @@ static unsafe uint GetFullTokenReference (string assembly_name, int module_token
 		{
 			var map = Runtime.options->RegistrationMap;
 			for (int i = 0; i < map->full_token_reference_count; i++) {
-				var ptr = map->full_token_references + (i * (IntPtr.Size + 8));
-				var asm_ptr = Marshal.ReadIntPtr (ptr);
-				var token = Marshal.ReadInt32 (ptr + IntPtr.Size + 4);
+				var ftr = map->full_token_references [i];
+				var token = ftr.token;
 				if (token != metadata_token)
 					continue;
-				var mod_token = Marshal.ReadInt32 (ptr + IntPtr.Size);
+				var mod_token = ftr.module_token;
 				if (mod_token != module_token)
 					continue;
-				if (!Runtime.StringEquals (asm_ptr, assembly_name))
+				var assembly_index = ftr.assembly_index;
+				var assembly = map->assemblies [assembly_index];
+				if (!Runtime.StringEquals (assembly.name, assembly_name))
 					continue;
 
 				return ((uint) i << 1) + 1;

src/ObjCRuntime/Runtime.cs

@@ -55,9 +55,9 @@ public partial class Runtime {
 
 #pragma warning disable 649 // Field 'X' is never assigned to, and will always have its default value
 		internal unsafe struct MTRegistrationMap {
-			public IntPtr assembly;
+			public MTAssembly *assemblies;
 			public MTClassMap *map;
-			public IntPtr full_token_references; /* array of MTFullTokenReference */
+			public MTFullTokenReference *full_token_references;
 			public MTManagedClassMap* skipped_map;
 			public MTProtocolWrapperMap* protocol_wrapper_map;
 			public MTProtocolMap protocol_map;
@@ -78,6 +78,13 @@ internal enum MTTypeFlags : uint
 			UserType = 2,
 		}
 
+		[StructLayout (LayoutKind.Sequential, Pack = 1)]
+		internal unsafe struct MTFullTokenReference {
+			public uint assembly_index;
+			public uint module_token;
+			public uint token;
+		}
+
 		[StructLayout (LayoutKind.Sequential, Pack = 1)]
 		internal struct MTClassMap {
 			public IntPtr handle;
@@ -104,6 +111,12 @@ internal unsafe struct MTProtocolMap {
 			public IntPtr* protocols;
 		}
 
+		[StructLayout (LayoutKind.Sequential, Pack = 1)]
+		internal unsafe struct MTAssembly {
+			public IntPtr name;
+			public IntPtr mvid;
+		}
+
 		/* Keep Delegates, Trampolines and InitializationOptions in sync with monotouch-glue.m */
 #pragma warning disable 649 // Field 'X' is never assigned to, and will always have its default value
 		internal struct Trampolines {

tests/dotnet/MyRegistrarApp/AppDelegate.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Runtime.InteropServices;
+
+using Foundation;
+using ObjCRuntime;
+
+namespace MySimpleApp
+{
+	public class Program
+	{
+		static int Main (string[] args)
+		{
+			Console.WriteLine (Environment.GetEnvironmentVariable ("MAGIC_WORD"));
+
+#if INCLUDED_ADDITIONAL_CODE
+			GC.KeepAlive (typeof (AdditionalClass));
+#endif
+
+			return StaticRegistrarValidationTest ();
+		}
+
+		static int StaticRegistrarValidationTest ()
+		{
+			try {
+				using var obj = new SomeObj ();
+				obj.Whatever ();
+				xamarin_IntPtr_objc_msgSend_IntPtr_ref_IntPtr_exception (obj.Handle, Selector.GetHandle ("whatever"), IntPtr.Zero, IntPtr.Zero, out var gchandle);
+				Console.WriteLine ($"GCH: {gchandle}");
+				if (gchandle != IntPtr.Zero) {
+					var gch = GCHandle.FromIntPtr (gchandle);
+					var exc = (Exception) gch.Target;
+					gch.Free ();
+					throw exc;
+				}
+				return 1; // We're not supposed to get here
+			} catch (Exception e) {
+				Console.WriteLine ($"E: {e}");
+				if (e.Message.Contains ("The assembly MyRegistrarApp has been modified since the app was built, invalidating the generated static registrar code."))
+					return 0;
+				return 2;
+			}
+		}
+
+		[DllImport ("__Internal")]
+		static extern IntPtr xamarin_IntPtr_objc_msgSend_IntPtr_ref_IntPtr_exception (IntPtr handle, IntPtr selector, IntPtr p0, IntPtr p1, out IntPtr gchandle);
+	}
+
+	public class SomeObj : NSObject
+	{
+		[Export ("whatever")]
+		public IntPtr Whatever ()
+		{
+			return new IntPtr (0xdeadf00d);
+		}
+	}
+
+	public class DeadClass {} // Some code for the linker to remove
+
+#if INCLUDED_ADDITIONAL_CODE
+	public class AdditionalClass {
+	}
+#endif
+}

tests/dotnet/MyRegistrarApp/MacCatalyst/Makefile

@@ -0,0 +1 @@
+include ../shared.mk

tests/dotnet/MyRegistrarApp/MacCatalyst/MyRegistrarApp.csproj

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-maccatalyst</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>

tests/dotnet/MyRegistrarApp/Makefile

@@ -0,0 +1,2 @@
+TOP=../../..
+include $(TOP)/tests/common/shared-dotnet-test.mk

tests/dotnet/MyRegistrarApp/iOS/Makefile

@@ -0,0 +1 @@
+include ../shared.mk

tests/dotnet/MyRegistrarApp/iOS/MyRegistrarApp.csproj

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-ios</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>

tests/dotnet/MyRegistrarApp/macOS/Makefile

@@ -0,0 +1 @@
+include ../shared.mk

tests/dotnet/MyRegistrarApp/macOS/MyRegistrarApp.csproj

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-macos</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>

tests/dotnet/MyRegistrarApp/shared.csproj

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+	<PropertyGroup>
+		<OutputType>Exe</OutputType>
+
+		<ApplicationTitle>MyRegistrarApp</ApplicationTitle>
+		<ApplicationId>com.xamarin.myregistrarapp</ApplicationId>
+
+		<ExcludeNUnitLiteReference>true</ExcludeNUnitLiteReference>
+		<ExcludeTouchUnitReference>true</ExcludeTouchUnitReference>
+
+		<DefineConstants>$(DefineConstants);$(AdditionalDefineConstants)</DefineConstants>
+	</PropertyGroup>
+
+	<Import Project="../../common/shared-dotnet.csproj" />
+
+	<ItemGroup>
+		<Compile Include="../*.cs" />
+	</ItemGroup>
+</Project>

tests/dotnet/MyRegistrarApp/shared.mk

@@ -0,0 +1,3 @@
+TOP=../../../..
+TESTNAME=MyRegistrarApp
+include $(TOP)/tests/common/shared-dotnet.mk

tests/dotnet/MyRegistrarApp/tvOS/Makefile

@@ -0,0 +1 @@
+include ../shared.mk