[mono] Don't access MonoClassField:parent directly (#63081)

Rename it to parent_ and add m_field_get_parent / m_field_set_parent accessors.

(The intention is to borrow the bottom bit of the pointer for an EnC metadata
update flag)

Author: lambdageek

src/mono/mono/component/debugger-agent.c

@@ -2932,7 +2932,7 @@ static gint32 isFixedSizeArray (MonoClassField *f)
 	MonoCustomAttrEntry *attr;
 	int aindex;
 	gint32 ret = 1;
-	cinfo = mono_custom_attrs_from_field_checked (f->parent, f, error);
+	cinfo = mono_custom_attrs_from_field_checked (m_field_get_parent (f), f, error);
 	goto_if_nok (error, leave);
 	attr = NULL;
 	if (cinfo) {
@@ -7734,12 +7734,12 @@ field_commands (int command, guint8 *p, guint8 *end, Buffer *buf)
 		MonoClassField *f = decode_fieldid (p, &p, end, &domain, &err);
 
 		buffer_add_string (buf, f->name);
-		buffer_add_typeid (buf, domain, f->parent);
+		buffer_add_typeid (buf, domain, m_field_get_parent (f));
 		buffer_add_typeid (buf, domain, mono_class_from_mono_type_internal (f->type));
 		buffer_add_int (buf, f->type->attrs);
 		if (CHECK_PROTOCOL_VERSION (2, 59)) {
 			buffer_add_int (buf, f->type->type);
-			buffer_add_int (buf, m_class_get_type_token (f->parent));
+			buffer_add_int (buf, m_class_get_type_token (m_field_get_parent (f)));
 			buffer_add_int (buf, m_class_get_type_token (mono_class_from_mono_type_internal (f->type)));
 		}
 		break;
@@ -7796,15 +7796,15 @@ static int get_static_field_value(MonoClassField* f, MonoClass* klass, MonoDomai
 	/* Check that the field belongs to the object */
 	found = FALSE;
 	for (k = klass; k; k = m_class_get_parent(k)) {
-		if (k == f->parent) {
+		if (k == m_field_get_parent (f)) {
 			found = TRUE;
 			break;
 		}
 	}
 	if (!found)
 		return -1;
 
-	vtable = mono_class_vtable_checked(f->parent, error);
+	vtable = mono_class_vtable_checked(m_field_get_parent (f), error);
 	if (!is_ok(error))
 		return -1;
 
@@ -8127,7 +8127,7 @@ type_commands_internal (int command, MonoClass *klass, MonoDomain *domain, guint
 			/* Check that the field belongs to the object */
 			found = FALSE;
 			for (k = klass; k; k = m_class_get_parent (k)) {
-				if (k == f->parent) {
+				if (k == m_field_get_parent (f)) {
 					found = TRUE;
 					break;
 				}
@@ -8137,7 +8137,7 @@ type_commands_internal (int command, MonoClass *klass, MonoDomain *domain, guint
 
 			// FIXME: Check for literal/const
 
-			vtable = mono_class_vtable_checked (f->parent, error);
+			vtable = mono_class_vtable_checked (m_field_get_parent (f), error);
 			goto_if_nok (error, invalid_fieldid);
 
 			val = (guint8 *)g_malloc (mono_class_instance_size (mono_class_from_mono_type_internal (f->type)));
@@ -9634,7 +9634,7 @@ object_commands (int command, guint8 *p, guint8 *end, Buffer *buf)
 			/* Check that the field belongs to the object */
 			found = FALSE;
 			for (k = obj_type; k; k = m_class_get_parent (k)) {
-				if (k == f->parent) {
+				if (k == m_field_get_parent (f)) {
 					found = TRUE;
 					break;
 				}
@@ -9650,7 +9650,7 @@ object_commands (int command, guint8 *p, guint8 *end, Buffer *buf)
 					goto invalid_fieldid;
 
 				g_assert (f->type->attrs & FIELD_ATTRIBUTE_STATIC);
-				vtable = mono_class_vtable_checked (f->parent, error);
+				vtable = mono_class_vtable_checked (m_field_get_parent (f), error);
 				if (!is_ok (error)) {
 					mono_error_cleanup (error);
 					goto invalid_object;
@@ -9681,7 +9681,7 @@ object_commands (int command, guint8 *p, guint8 *end, Buffer *buf)
 			/* Check that the field belongs to the object */
 			found = FALSE;
 			for (k = obj_type; k; k = m_class_get_parent (k)) {
-				if (k == f->parent) {
+				if (k == m_field_get_parent (f)) {
 					found = TRUE;
 					break;
 				}
@@ -9697,7 +9697,7 @@ object_commands (int command, guint8 *p, guint8 *end, Buffer *buf)
 					goto invalid_fieldid;
 
 				g_assert (f->type->attrs & FIELD_ATTRIBUTE_STATIC);
-				vtable = mono_class_vtable_checked (f->parent, error);
+				vtable = mono_class_vtable_checked (m_field_get_parent (f), error);
 				if (!is_ok (error)) {
 					mono_error_cleanup (error);
 					goto invalid_fieldid;

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

@@ -204,7 +204,7 @@ mono_class_setup_basic_field_info (MonoClass *klass)
 	int first_field_idx = mono_class_has_static_metadata (klass) ? mono_class_get_first_field_idx (klass) : 0;
 	for (i = 0; i < top; i++) {
 		field = &fields [i];
-		field->parent = klass;
+		m_field_set_parent (field, klass);
 
 		if (gtd) {
 			field->name = mono_field_get_name (&gtd->fields [i]);
@@ -2399,7 +2399,7 @@ mono_class_layout_fields (MonoClass *klass, int base_instance_size, int packing_
 				guint32 field_idx = first_field_idx + (field - p->fields);
 				if (MONO_TYPE_IS_REFERENCE (field->type) && mono_assembly_is_weak_field (p->image, field_idx + 1)) {
 					has_weak_fields = TRUE;
-					mono_trace_message (MONO_TRACE_TYPE, "Field %s:%s at offset %x is weak.", field->parent->name, field->name, field->offset);
+					mono_trace_message (MONO_TRACE_TYPE, "Field %s:%s at offset %x is weak.", m_field_get_parent (field)->name, field->name, field->offset);
 				}
 			}
 		}
@@ -4080,3 +4080,9 @@ mono_classes_init (void)
 	mono_counters_register ("MonoClass size",
 							MONO_COUNTER_METADATA | MONO_COUNTER_INT, &classes_size);
 }
+
+void
+m_field_set_parent (MonoClassField *field, MonoClass *klass)
+{
+	field->parent_ = klass;
+}

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

@@ -146,7 +146,8 @@ struct _MonoClassField {
 	const char      *name;
 
 	/* Type where the field was defined */
-	MonoClass       *parent;
+	/* Do not access directly, use m_field_get_parent */
+	MonoClass       *parent_;
 
 	/*
 	 * Offset where this field is stored; if it is an instance
@@ -1535,10 +1536,19 @@ mono_method_has_unmanaged_callers_only_attribute (MonoMethod *method);
 		}								\
 	}									\
 
+static inline MonoClass *
+m_field_get_parent (MonoClassField *field)
+{
+	return field->parent_;
+}
+
+void
+m_field_set_parent (MonoClassField *field, MonoClass *klass);
+
 static inline gboolean
 m_field_get_offset (MonoClassField *field)
 {
-	g_assert (m_class_is_fields_inited (field->parent));
+	g_assert (m_class_is_fields_inited (m_field_get_parent (field)));
 	return field->offset;
 }
 

src/mono/mono/metadata/class.c

@@ -2501,7 +2501,7 @@ mono_class_get_field_from_name_full (MonoClass *klass, const char *name, MonoTyp
 guint32
 mono_class_get_field_token (MonoClassField *field)
 {
-	MonoClass *klass = field->parent;
+	MonoClass *klass = m_field_get_parent (field);
 	int i;
 
 	mono_class_setup_fields (klass);
@@ -2531,8 +2531,8 @@ mono_class_get_field_token (MonoClassField *field)
 static int
 mono_field_get_index (MonoClassField *field)
 {
-	int index = field - m_class_get_fields (field->parent);
-	g_assert (index >= 0 && index < mono_class_get_field_count (field->parent));
+	int index = field - m_class_get_fields (m_field_get_parent (field));
+	g_assert (index >= 0 && index < mono_class_get_field_count (m_field_get_parent (field)));
 
 	return index;
 }
@@ -2548,7 +2548,7 @@ mono_class_get_field_default_value (MonoClassField *field, MonoTypeEnum *def_typ
 	guint32 cindex;
 	guint32 constant_cols [MONO_CONSTANT_SIZE];
 	int field_index;
-	MonoClass *klass = field->parent;
+	MonoClass *klass = m_field_get_parent (field);
 	MonoFieldDefaultValue *def_values;
 
 	g_assert (field->type->attrs & FIELD_ATTRIBUTE_HAS_DEFAULT);
@@ -2563,7 +2563,7 @@ mono_class_get_field_default_value (MonoClassField *field, MonoTypeEnum *def_typ
 	field_index = mono_field_get_index (field);
 
 	if (!def_values [field_index].data) {
-		MonoImage *field_parent_image = m_class_get_image (field->parent);
+		MonoImage *field_parent_image = m_class_get_image (m_field_get_parent (field));
 		cindex = mono_metadata_get_constant_index (field_parent_image, mono_class_get_field_token (field), 0);
 		if (!cindex)
 			return NULL;
@@ -5402,7 +5402,7 @@ mono_field_get_type_checked (MonoClassField *field, MonoError *error)
 MonoClass*
 mono_field_get_parent (MonoClassField *field)
 {
-	return field->parent;
+	return m_field_get_parent (field);
 }
 
 /**
@@ -5431,7 +5431,7 @@ mono_field_get_flags (MonoClassField *field)
 guint32
 mono_field_get_offset (MonoClassField *field)
 {
-	mono_class_setup_fields(field->parent);
+	mono_class_setup_fields(m_field_get_parent (field));
 	return field->offset;
 }
 
@@ -5440,7 +5440,7 @@ mono_field_get_rva (MonoClassField *field, int swizzle)
 {
 	guint32 rva;
 	int field_index;
-	MonoClass *klass = field->parent;
+	MonoClass *klass = m_field_get_parent (field);
 	MonoFieldDefaultValue *def_values;
 
 	g_assert (field->type->attrs & FIELD_ATTRIBUTE_HAS_FIELD_RVA);
@@ -5459,11 +5459,11 @@ mono_field_get_rva (MonoClassField *field, int swizzle)
 
 		if (!image_is_dynamic (m_class_get_image (klass))) {
 			int first_field_idx = mono_class_get_first_field_idx (klass);
-			mono_metadata_field_info (m_class_get_image (field->parent), first_field_idx + field_index, NULL, &rva, NULL);
+			mono_metadata_field_info (m_class_get_image (m_field_get_parent (field)), first_field_idx + field_index, NULL, &rva, NULL);
 			if (!rva)
-				g_warning ("field %s in %s should have RVA data, but hasn't", mono_field_get_name (field), m_class_get_name (field->parent));
+				g_warning ("field %s in %s should have RVA data, but hasn't", mono_field_get_name (field), m_class_get_name (m_field_get_parent (field)));
 
-			rvaData = mono_image_rva_map (m_class_get_image (field->parent), rva);
+			rvaData = mono_image_rva_map (m_class_get_image (m_field_get_parent (field)), rva);
 		} else {
 			rvaData = mono_field_get_data (field);
 		}
@@ -6170,11 +6170,11 @@ gboolean
 mono_method_can_access_field (MonoMethod *method, MonoClassField *field)
 {
 	/* FIXME: check all overlapping fields */
-	int can = can_access_member (method->klass, field->parent, NULL, mono_field_get_type_internal (field)->attrs & FIELD_ATTRIBUTE_FIELD_ACCESS_MASK);
+	int can = can_access_member (method->klass, m_field_get_parent (field), NULL, mono_field_get_type_internal (field)->attrs & FIELD_ATTRIBUTE_FIELD_ACCESS_MASK);
 	if (!can) {
 		MonoClass *nested = m_class_get_nested_in (method->klass);
 		while (nested) {
-			can = can_access_member (nested, field->parent, NULL, mono_field_get_type_internal (field)->attrs & FIELD_ATTRIBUTE_FIELD_ACCESS_MASK);
+			can = can_access_member (nested, m_field_get_parent (field), NULL, mono_field_get_type_internal (field)->attrs & FIELD_ATTRIBUTE_FIELD_ACCESS_MASK);
 			if (can)
 				return TRUE;
 			nested = m_class_get_nested_in (nested);
@@ -6282,7 +6282,7 @@ gboolean
 mono_method_can_access_field_full (MonoMethod *method, MonoClassField *field, MonoClass *context_klass)
 {
 	MonoClass *access_class = method->klass;
-	MonoClass *member_class = field->parent;
+	MonoClass *member_class = m_field_get_parent (field);
 	/* FIXME: check all overlapping fields */
 	int can = can_access_member (access_class, member_class, context_klass, field->type->attrs & FIELD_ATTRIBUTE_FIELD_ACCESS_MASK);
 	if (!can) {
@@ -6413,7 +6413,7 @@ mono_generic_class_is_generic_type_definition (MonoGenericClass *gklass)
 void
 mono_field_resolve_type (MonoClassField *field, MonoError *error)
 {
-	MonoClass *klass = field->parent;
+	MonoClass *klass = m_field_get_parent (field);
 	MonoImage *image = m_class_get_image (klass);
 	MonoClass *gtd = mono_class_is_ginst (klass) ? mono_class_get_generic_type_definition (klass) : NULL;
 	MonoType *ftype;
@@ -6475,7 +6475,7 @@ mono_field_resolve_type (MonoClassField *field, MonoError *error)
 static guint32
 mono_field_resolve_flags (MonoClassField *field)
 {
-	MonoClass *klass = field->parent;
+	MonoClass *klass = m_field_get_parent (field);
 	MonoImage *image = m_class_get_image (klass);
 	MonoClass *gtd = mono_class_is_ginst (klass) ? mono_class_get_generic_type_definition (klass) : NULL;
 	int field_idx = field - m_class_get_fields (klass);

src/mono/mono/metadata/custom-attrs.c

@@ -2132,7 +2132,7 @@ mono_reflection_get_custom_attrs_info_checked (MonoObjectHandle obj, MonoError *
 	} else if (strcmp ("RuntimeFieldInfo", klass_name) == 0) {
 		MonoReflectionFieldHandle rfield = MONO_HANDLE_CAST (MonoReflectionField, obj);
 		MonoClassField *field = MONO_HANDLE_GETVAL (rfield, field);
-		cinfo = mono_custom_attrs_from_field_checked (field->parent, field, error);
+		cinfo = mono_custom_attrs_from_field_checked (m_field_get_parent (field), field, error);
 		goto_if_nok (error, leave);
 	} else if ((strcmp ("RuntimeMethodInfo", klass_name) == 0) || (strcmp ("RuntimeConstructorInfo", klass_name) == 0)) {
 		MonoReflectionMethodHandle rmethod = MONO_HANDLE_CAST (MonoReflectionMethod, obj);

src/mono/mono/metadata/debug-helpers.c

@@ -868,10 +868,10 @@ char *
 mono_field_full_name (MonoClassField *field)
 {
 	char *res;
-	const char *nspace = field->parent->name_space;
+	const char *nspace = m_field_get_parent (field)->name_space;
 
 	res = g_strdup_printf ("%s%s%s:%s", nspace, *nspace ? "." : "",
-						   field->parent->name, mono_field_get_name (field));
+						   m_field_get_parent (field)->name, mono_field_get_name (field));
 
 	return res;
 }