Copy allocator to subclasses at boot and on change

Copy the allocator from superclass to subclass at class creation time,
so rb_get_alloc_func no longer needs to walk the ancestor chain.

This expands on 68ffc8db088a7b29613a3746be5cc996be9f66fe, which did this
copy, but only for classes defined in Ruby (ex. `class Foo`). And allows
us to simple read the allocator field for any class to get the correct
value.

To keep this correct when rb_define_alloc_func is called after
subclasses already exist, propagate the new allocator down to all
subclasses. An RCLASS_ALLOCATOR_DEFINED flag distinguishes classes with
an explicitly set allocator from those that inherited one, so
propagation stops at subclasses that define their own.

1 files changed, 1 insertions, 1 deletions

diff --git a/object.c b/object.c
index 4dcd5d615f..c3241a198d 100644
--- a/object.c
+++ b/object.c
@@ -2253,6 +2253,7 @@ rb_class_initialize(int argc, VALUE *argv, VALUE klass)
         }
     }
     rb_class_set_super(klass, super);
+    RCLASS_SET_ALLOCATOR(klass, RCLASS_ALLOCATOR(super));
     rb_make_metaclass(klass, RBASIC(super)->klass);
     rb_class_inherited(super, klass);
     rb_mod_initialize_exec(klass);
@@ -4448,7 +4449,6 @@ InitVM_Object(void)
 #endif
 
     rb_define_private_method(rb_cBasicObject, "initialize", rb_obj_initialize, 0);
-    rb_define_alloc_func(rb_cBasicObject, rb_class_allocate_instance);
     rb_define_method(rb_cBasicObject, "==", rb_obj_equal, 1);
     rb_define_method(rb_cBasicObject, "equal?", rb_obj_equal, 1);
     rb_define_method(rb_cBasicObject, "!", rb_obj_not, 0);