Throw InvalidOperationException on RuntimeMethodHandle.GetFunctionPointer() for generic methods (#104644)

* Throw InvalidOperationException on RuntimeMethodHandle.GetFunctionPointer() for generic methods

* Also check if owning type is generic; add checks to mono interpreter

* Update src/coreclr/vm/method.cpp

---------

Co-authored-by: Buyaa Namnan <[email protected]>

Author: steveharter

src/coreclr/vm/method.cpp

@@ -2136,10 +2136,9 @@ PCODE MethodDesc::TryGetMultiCallableAddrOfCode(CORINFO_ACCESS_FLAGS accessFlags
     }
     CONTRACTL_END
 
-    if (IsGenericMethodDefinition())
+    if (ContainsGenericVariables())
     {
-        _ASSERTE(!"Cannot take the address of an uninstantiated generic method.");
-        COMPlusThrow(kInvalidProgramException);
+        COMPlusThrow(kInvalidOperationException, IDS_EE_CODEEXECUTION_CONTAINSGENERICVAR);
     }
 
     if (accessFlags & CORINFO_ACCESS_LDFTN)

src/libraries/System.Runtime/tests/System.Reflection.Tests/MethodInfoTests.cs

@@ -306,6 +306,39 @@ public void InvokeUninstantiatedGenericMethod()
             Assert.Throws<InvalidOperationException>(() => GetMethod(typeof(MI_SubClass), nameof(MI_SubClass.StaticGenericMethod)).Invoke(null, [null]));
         }
 
+        [Fact]
+        public void InvokeUninstantiatedGenericType_GenericMethod()
+        {
+            Assert.Throws<InvalidOperationException>(() => GetMethod(typeof(MI_GenericClass<>), "GenericMethod4").Invoke(null, [null]));
+        }
+
+        [Fact]
+        public void InvokeUninstantiatedGenericType_NonGenericMethod()
+        {
+            Assert.Throws<InvalidOperationException>(() => GetMethod(typeof(MI_GenericClass<>), "NonGenericMethod").Invoke(null, [null]));
+        }
+
+        [Fact]
+        public void GetFunctionPointerFromUninstantiatedGenericMethod()
+        {
+            RuntimeMethodHandle handle = typeof(MI_SubClass).GetMethod(nameof(MI_SubClass.StaticGenericMethod))!.MethodHandle;
+            Assert.Throws<InvalidOperationException>(() => handle.GetFunctionPointer());
+        }
+
+        [Fact]
+        public void GetFunctionPointerOnUninstantiatedGenericType_GenericMethod()
+        {
+            RuntimeMethodHandle handle = typeof(MI_GenericClass<>).GetMethod("GenericMethod4")!.MethodHandle;
+            Assert.Throws<InvalidOperationException>(() => handle.GetFunctionPointer());
+        }
+
+        [Fact]
+        public void GetFunctionPointerOnUninstantiatedGenericType_NonGenericMethod()
+        {
+            RuntimeMethodHandle handle = typeof(MI_GenericClass<>).GetMethod("NonGenericMethod")!.MethodHandle;
+            Assert.Throws<InvalidOperationException>(() => handle.GetFunctionPointer());
+        }
+
         [Fact]
         public void GetHashCodeTest()
         {
@@ -799,6 +832,8 @@ public class MI_GenericClass<T>
         public T GenericMethod1(T t) => t;
         public T GenericMethod2<S>(S s1, T t, string s2) => t;
         public static S GenericMethod3<S>(S s) => s;
+        public static T GenericMethod4(T s) => s;
+        public static void NonGenericMethod() { }
     }
 
     public interface MethodInfoBaseDefinitionInterface

src/mono/mono/mini/interp/interp.c

@@ -7476,6 +7476,11 @@ MINT_IN_CASE(MINT_BRTRUE_I8_SP) ZEROP_SP(gint64, !=); MINT_IN_BREAK;
 
 			MonoMethod *local_cmethod = LOCAL_VAR (ip [2], MonoMethod*);
 
+			if (local_cmethod->is_generic || mono_class_is_gtd (local_cmethod->klass)) {
+				MonoException *ex = mono_exception_from_name_msg (mono_defaults.corlib, "System", "InvalidOperationException", "");
+				THROW_EX (ex, ip);
+			}			
+
 			// FIXME push/pop LMF
 			if (G_UNLIKELY (mono_method_has_unmanaged_callers_only_attribute (local_cmethod))) {
 				local_cmethod = mono_marshal_get_managed_wrapper  (local_cmethod, NULL, (MonoGCHandle)0, error);

src/mono/mono/mini/mini-runtime.c

@@ -2939,6 +2939,11 @@ mono_jit_compile_method_jit_only (MonoMethod *method, MonoError *error)
 static gpointer
 get_ftnptr_for_method (MonoMethod *method, gboolean need_unbox, MonoError *error)
 {
+	if (method->is_generic || mono_class_is_gtd (method->klass)) {
+		mono_error_set_generic_error (error, "System", "InvalidOperationException", "");
+		return NULL;
+	}
+
 	if (!mono_llvm_only) {
 		gpointer res = mono_jit_compile_method (method, error);
 		res = mini_add_method_trampoline (method, res, mono_method_needs_static_rgctx_invoke (method, TRUE), need_unbox);