Add RCLASS_SUBCLASSES Macro

class.c

@@ -53,14 +53,14 @@ rb_class_subclass_add(VALUE super, VALUE klass)
 	entry->klass = klass;
 	entry->next = NULL;
 
-	head = RCLASS_EXT(super)->subclasses;
+	head = RCLASS_SUBCLASSES(super);
 	if (head) {
 	    entry->next = head;
 	    RCLASS_PARENT_SUBCLASSES(head->klass) = &entry->next;
 	}
 
-	RCLASS_EXT(super)->subclasses = entry;
-	RCLASS_PARENT_SUBCLASSES(klass) = &RCLASS_EXT(super)->subclasses;
+	RCLASS_SUBCLASSES(super) = entry;
+	RCLASS_PARENT_SUBCLASSES(klass) = &RCLASS_SUBCLASSES(super);
     }
 }
 
@@ -73,14 +73,14 @@ rb_module_add_to_subclasses_list(VALUE module, VALUE iclass)
     entry->klass = iclass;
     entry->next = NULL;
 
-    head = RCLASS_EXT(module)->subclasses;
+    head = RCLASS_SUBCLASSES(module);
     if (head) {
 	entry->next = head;
 	RCLASS_MODULE_SUBCLASSES(head->klass) = &entry->next;
     }
 
-    RCLASS_EXT(module)->subclasses = entry;
-    RCLASS_MODULE_SUBCLASSES(iclass) = &RCLASS_EXT(module)->subclasses;
+    RCLASS_SUBCLASSES(module) = entry;
+    RCLASS_MODULE_SUBCLASSES(iclass) = &RCLASS_SUBCLASSES(module);
 }
 
 void
@@ -123,7 +123,7 @@ rb_class_remove_from_module_subclasses(VALUE klass)
 void
 rb_class_foreach_subclass(VALUE klass, void (*f)(VALUE, VALUE), VALUE arg)
 {
-    rb_subclass_entry_t *cur = RCLASS_EXT(klass)->subclasses;
+    rb_subclass_entry_t *cur = RCLASS_SUBCLASSES(klass);
 
     /* do not be tempted to simplify this loop into a for loop, the order of
        operations is important here if `f` modifies the linked list */
@@ -181,7 +181,7 @@ class_alloc(VALUE flags, VALUE klass)
       RCLASS_M_TBL(obj) = 0;
       RCLASS_IV_INDEX_TBL(obj) = 0;
       RCLASS_SET_SUPER((VALUE)obj, 0);
-      RCLASS_EXT(obj)->subclasses = NULL;
+      RCLASS_SUBCLASSES(obj) = NULL;
       RCLASS_PARENT_SUBCLASSES(obj) = NULL;
       RCLASS_MODULE_SUBCLASSES(obj) = NULL;
      */
@@ -979,7 +979,7 @@ rb_include_module(VALUE klass, VALUE module)
 	rb_raise(rb_eArgError, "cyclic include detected");
 
     if (RB_TYPE_P(klass, T_MODULE)) {
-        rb_subclass_entry_t *iclass = RCLASS_EXT(klass)->subclasses;
+        rb_subclass_entry_t *iclass = RCLASS_SUBCLASSES(klass);
         int do_include = 1;
         while (iclass) {
             VALUE check_class = iclass->klass;
@@ -1190,7 +1190,7 @@ rb_prepend_module(VALUE klass, VALUE module)
 	rb_vm_check_redefinition_by_prepend(klass);
     }
     if (RB_TYPE_P(klass, T_MODULE)) {
-        rb_subclass_entry_t *iclass = RCLASS_EXT(klass)->subclasses;
+        rb_subclass_entry_t *iclass = RCLASS_SUBCLASSES(klass);
         VALUE klass_origin = RCLASS_ORIGIN(klass);
         struct rb_id_table *klass_m_tbl = RCLASS_M_TBL(klass);
         struct rb_id_table *klass_origin_m_tbl = RCLASS_M_TBL(klass_origin);

gc.c

@@ -2836,14 +2836,14 @@ obj_free(rb_objspace_t *objspace, VALUE obj)
 	if (RCLASS_IV_INDEX_TBL(obj)) {
             iv_index_tbl_free(RCLASS_IV_INDEX_TBL(obj));
 	}
-	if (RCLASS_EXT(obj)->subclasses) {
+	if (RCLASS_SUBCLASSES(obj)) {
 	    if (BUILTIN_TYPE(obj) == T_MODULE) {
 		rb_class_detach_module_subclasses(obj);
 	    }
 	    else {
 		rb_class_detach_subclasses(obj);
 	    }
-	    RCLASS_EXT(obj)->subclasses = NULL;
+	    RCLASS_SUBCLASSES(obj) = NULL;
 	}
 	rb_class_remove_from_module_subclasses(obj);
 	rb_class_remove_from_super_subclasses(obj);
@@ -3008,9 +3008,9 @@ obj_free(rb_objspace_t *objspace, VALUE obj)
 	if (RCLASS_CALLABLE_M_TBL(obj) != NULL) {
 	    rb_id_table_free(RCLASS_CALLABLE_M_TBL(obj));
 	}
-	if (RCLASS_EXT(obj)->subclasses) {
+	if (RCLASS_SUBCLASSES(obj)) {
 	    rb_class_detach_subclasses(obj);
-	    RCLASS_EXT(obj)->subclasses = NULL;
+	    RCLASS_SUBCLASSES(obj) = NULL;
 	}
         cc_table_free(objspace, obj, FALSE);
 	rb_class_remove_from_module_subclasses(obj);

internal/class.h

@@ -95,6 +95,7 @@ typedef struct rb_classext_struct rb_classext_t;
 #define RCLASS_PARENT_SUBCLASSES(c) (RCLASS_EXT(c)->parent_subclasses)
 #define RCLASS_MODULE_SUBCLASSES(c) (RCLASS_EXT(c)->module_subclasses)
 #define RCLASS_ALLOCATOR(c) (RCLASS_EXT(c)->allocator)
+#define RCLASS_SUBCLASSES(c) (RCLASS_EXT(c)->subclasses)
 
 #define RICLASS_IS_ORIGIN FL_USER5
 #define RCLASS_CLONED     FL_USER6

vm_method.c

@@ -153,7 +153,7 @@ clear_method_cache_by_id_in_class(VALUE klass, ID mid)
     VM_ASSERT(RB_TYPE_P(klass, T_CLASS) || RB_TYPE_P(klass, T_ICLASS));
     if (rb_objspace_garbage_object_p(klass)) return;
 
-    if (LIKELY(RCLASS_EXT(klass)->subclasses == NULL)) {
+    if (LIKELY(RCLASS_SUBCLASSES(klass) == NULL)) {
         // no subclasses
         // check only current class