[mono] Add basic ref struct support for generic parameter

src/mono/mono/metadata/class-init.c

@@ -2953,7 +2953,7 @@ mono_class_init_internal (MonoClass *klass)
 	if (klass->inited || mono_class_has_failure (klass))
 		return !mono_class_has_failure (klass);
 
-	/*g_print ("Init class %s\n", mono_type_get_full_name (klass));*/
+	// g_print ("Init class %s\n", mono_type_get_full_name (klass));
 
 	/*
 	 * This function can recursively call itself.

src/mono/mono/metadata/class.c

@@ -640,10 +640,7 @@ mono_type_is_valid_generic_argument (MonoType *type)
 {
 	switch (type->type) {
 	case MONO_TYPE_VOID:
-	case MONO_TYPE_TYPEDBYREF:
 		return FALSE;
-	case MONO_TYPE_VALUETYPE:
-		return !m_class_is_byreflike (type->data.klass);
 	default:
 		return TRUE;
 	}

src/mono/mono/metadata/loader.c

@@ -823,7 +823,6 @@ mono_method_search_in_array_class (MonoClass *klass, const char *name, MonoMetho
 	int i;
 
 	mono_class_setup_methods (klass);
-	g_assert (!mono_class_has_failure (klass)); /*FIXME this should not fail, right?*/
 	int mcount = mono_class_get_method_count (klass);
 	MonoMethod **klass_methods = m_class_get_methods (klass);
 	for (i = 0; i < mcount; ++i) {

src/mono/mono/metadata/object-internals.h

@@ -1439,16 +1439,17 @@ typedef struct {
 
 /* Keep in sync with System.GenericParameterAttributes */
 typedef enum {
-	GENERIC_PARAMETER_ATTRIBUTE_NON_VARIANT		= 0,
-	GENERIC_PARAMETER_ATTRIBUTE_COVARIANT		= 1,
-	GENERIC_PARAMETER_ATTRIBUTE_CONTRAVARIANT	= 2,
-	GENERIC_PARAMETER_ATTRIBUTE_VARIANCE_MASK	= 3,
-
-	GENERIC_PARAMETER_ATTRIBUTE_NO_SPECIAL_CONSTRAINT	= 0,
-	GENERIC_PARAMETER_ATTRIBUTE_REFERENCE_TYPE_CONSTRAINT	= 4,
-	GENERIC_PARAMETER_ATTRIBUTE_VALUE_TYPE_CONSTRAINT	= 8,
-	GENERIC_PARAMETER_ATTRIBUTE_CONSTRUCTOR_CONSTRAINT	= 16,
-	GENERIC_PARAMETER_ATTRIBUTE_SPECIAL_CONSTRAINTS_MASK	= 28
+	GENERIC_PARAMETER_ATTRIBUTE_NON_VARIANT		= 0x0000,
+	GENERIC_PARAMETER_ATTRIBUTE_COVARIANT		= 0x0001,
+	GENERIC_PARAMETER_ATTRIBUTE_CONTRAVARIANT	= 0x0002,
+	GENERIC_PARAMETER_ATTRIBUTE_VARIANCE_MASK	= 0x0003,
+
+	GENERIC_PARAMETER_ATTRIBUTE_NO_SPECIAL_CONSTRAINT			= 0x0000,
+	GENERIC_PARAMETER_ATTRIBUTE_REFERENCE_TYPE_CONSTRAINT		= 0x0004,
+	GENERIC_PARAMETER_ATTRIBUTE_VALUE_TYPE_CONSTRAINT			= 0x0008,
+	GENERIC_PARAMETER_ATTRIBUTE_CONSTRUCTOR_CONSTRAINT			= 0x0010,
+	GENERIC_PARAMETER_ATTRIBUTE_ACCEPT_BYREFLIKE_CONSTRAINTS	= 0x0020,	// type argument can be ByRefLike
+	GENERIC_PARAMETER_ATTRIBUTE_SPECIAL_CONSTRAINTS_MASK		= 0x003c
 } GenericParameterAttributes;
 
 typedef struct {

src/mono/mono/metadata/verify.c

@@ -87,6 +87,9 @@ is_valid_generic_instantiation (MonoGenericContainer *gc, MonoGenericContext *co
 				return FALSE;
 		}
 
+		if (m_class_is_byreflike (paramClass) && (param_info->flags & GENERIC_PARAMETER_ATTRIBUTE_ACCEPT_BYREFLIKE_CONSTRAINTS) == 0)
+			return FALSE;
+
 		if (!param_info->constraints && !(param_info->flags & GENERIC_PARAMETER_ATTRIBUTE_SPECIAL_CONSTRAINTS_MASK))
 			continue;
 

src/mono/mono/mini/method-to-ir.c

@@ -9277,7 +9277,7 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
 
 			mono_save_token_info (cfg, image, token, cmethod);
 
-			if (!mono_class_init_internal (cmethod->klass))
+			if (mono_class_has_failure (cmethod->klass) || !mono_class_init_internal (cmethod->klass))
 				TYPE_LOAD_ERROR (cmethod->klass);
 
 			context_used = mini_method_check_context_used (cfg, cmethod);

src/mono/mono/mini/mini-generic-sharing.c

@@ -590,6 +590,7 @@ inflate_info (MonoMemoryManager *mem_manager, MonoRuntimeGenericContextInfoTempl
 			inflated_method = mono_class_inflate_generic_method_checked (method, context, error);
 			g_assert (is_ok (error)); /* FIXME don't swallow the error */
 		}
+		g_assert (inflated_method);
 		mono_class_init_internal (inflated_method->klass);
 		g_assert (inflated_method->klass == inflated_class);
 		return inflated_method;
@@ -654,6 +655,7 @@ inflate_info (MonoMemoryManager *mem_manager, MonoRuntimeGenericContextInfoTempl
 			inflated_method = mono_class_inflate_generic_method_checked (method, context, error);
 			g_assert (is_ok (error)); /* FIXME don't swallow the error */
 		}
+		g_assert (inflated_method);
 		mono_class_init_internal (inflated_method->klass);
 		g_assert (inflated_method->klass == inflated_class);
 

src/tests/Loader/classloader/generics/ByRefLike/GenericTypeSubstitution.cs

@@ -12,7 +12,6 @@
 public class GenericTypeSubstitution
 {
     [Fact]
-    [SkipOnMono("Mono does not support ByRefLike generics yet")]
     public static void AllowByRefLike_Substituted_For_AllowByRefLike()
     {
         Console.WriteLine($"{nameof(AllowByRefLike_Substituted_For_AllowByRefLike)}...");
@@ -23,7 +22,6 @@ public static void AllowByRefLike_Substituted_For_AllowByRefLike()
     }
 
     [Fact]
-    [SkipOnMono("Mono does not support ByRefLike generics yet")]
     public static void NonByRefLike_Substituted_For_AllowByRefLike()
     {
         Console.WriteLine($" -- Instantiate: {Exec.TypeSubstitutionInterfaceImplementationNonByRefLike()}");

src/tests/Loader/classloader/generics/ByRefLike/InvalidCSharp.ilproj

@@ -2,7 +2,6 @@
   <PropertyGroup>
     <OutputType>library</OutputType>
     <MonoAotIncompatible>true</MonoAotIncompatible>
-    <DisableProjectBuild Condition="'$(RuntimeFlavor)' == 'Mono'">true</DisableProjectBuild>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="InvalidCSharp.il" />

src/tests/Loader/classloader/generics/ByRefLike/Validate.cs

@@ -12,7 +12,6 @@
 public class Validate
 {
     [Fact]
-    [SkipOnMono("Mono does not support ByRefLike generics yet")]
     public static void Validate_TypeLoad()
     {
         Console.WriteLine($"{nameof(Validate_TypeLoad)}...");
@@ -29,7 +28,6 @@ public static void Validate_TypeLoad()
     }
 
     [Fact]
-    [SkipOnMono("Mono does not support ByRefLike generics yet")]
     public static void Validate_Casting_Scenarios()
     {
         Console.WriteLine($"{nameof(Validate_Casting_Scenarios)}...");
@@ -44,7 +42,6 @@ public static void Validate_Casting_Scenarios()
     }
 
     [Fact]
-    [SkipOnMono("Mono does not support ByRefLike generics yet")]
     public static void Validate_RecognizedOpCodeSequences_Scenarios()
     {
         Console.WriteLine($"{nameof(Validate_RecognizedOpCodeSequences_Scenarios)}...");
@@ -64,16 +61,26 @@ public static void Validate_InvalidOpCode_Scenarios()
         // These methods uses opcodes that are not able to handle ByRefLike type operands.
         // The TypeLoader prevents these invalid types from being constructed. We rely on
         // the failure to construct these invalid types to block opcode usage.
-        Assert.Throws<TypeLoadException>(() => { Exec.AllocArrayOfT_Invalid(); });
-        Assert.Throws<TypeLoadException>(() => { Exec.AllocMultiDimArrayOfT_Invalid(); });
         Assert.Throws<TypeLoadException>(() => { Exec.GenericClassWithStaticField_Invalid(); });
 
         // Test that explicitly tries to box a ByRefLike type.
         Assert.Throws<InvalidProgramException>(() => { Exec.BoxAsObject(); });
     }
 
     [Fact]
-    [SkipOnMono("Mono does not support ByRefLike generics yet")]
+    public static void Validate_InvalidOpCode_Scenarios_ArrayOfT()
+    {
+        Console.WriteLine($"{nameof(Validate_InvalidOpCode_Scenarios_ArrayOfT)}...");
+
+        // These methods uses opcodes that are not able to handle ByRefLike type operands.
+        // The TypeLoader prevents these invalid types from being constructed. We rely on
+        // the failure to construct these invalid types to block opcode usage.
+
+        Assert.Throws<TypeLoadException>(() => { Exec.AllocArrayOfT_Invalid(); });
+        Assert.Throws<TypeLoadException>(() => { Exec.AllocMultiDimArrayOfT_Invalid(); });
+    }
+
+    [Fact]
     public static void Validate_Inlining_Behavior()
     {
         Console.WriteLine($"{nameof(Validate_Inlining_Behavior)}...");

src/tests/Loader/classloader/generics/ByRefLike/Validate.csproj

@@ -2,7 +2,6 @@
   <PropertyGroup>
     <!-- Needed for mechanical merging of all remaining tests, this particular project may not actually need process isolation -->
     <RequiresProcessIsolation>true</RequiresProcessIsolation>
-    <DisableProjectBuild Condition="'$(RuntimeFlavor)' == 'Mono'">true</DisableProjectBuild>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="Validate.cs" />