Encapsulate RCLASS_ATTACHED_OBJECT

Right now the attached object is stored as an instance variable
and all the call sites that either get or set it have to know how it's
stored.

It's preferable to hide this implementation detail behind accessors
so that it is easier to change how it's stored.

1 files changed, 7 insertions, 9 deletions

diff --git a/class.c b/class.c
index cf1731c1ab..1545cc0b9f 100644
--- a/class.c
+++ b/class.c
@@ -30,8 +30,6 @@
 #include "ruby/st.h"
 #include "vm_core.h"
 
-#define id_attached id__attached__
-
 #define METACLASS_OF(k) RBASIC(k)->klass
 #define SET_METACLASS_OF(k, cls) RBASIC_SET_CLASS(k, cls)
 
@@ -615,7 +613,7 @@ rb_singleton_class_clone_and_attach(VALUE obj, VALUE attach)
     // attached to an object other than `obj`. In which case `obj` does not have
     // a material singleton class attached yet and there is no singleton class
     // to clone.
-    if (!(FL_TEST(klass, FL_SINGLETON) && rb_attr_get(klass, id_attached) == obj)) {
+    if (!(FL_TEST(klass, FL_SINGLETON) && RCLASS_ATTACHED_OBJECT(klass) == obj)) {
         // nothing to clone
         return klass;
     }
@@ -668,7 +666,7 @@ void
 rb_singleton_class_attached(VALUE klass, VALUE obj)
 {
     if (FL_TEST(klass, FL_SINGLETON)) {
-        rb_class_ivar_set(klass, id_attached, obj);
+        RCLASS_SET_ATTACHED_OBJECT(klass, obj);
     }
 }
 
@@ -682,13 +680,13 @@ rb_singleton_class_attached(VALUE klass, VALUE obj)
 static int
 rb_singleton_class_has_metaclass_p(VALUE sklass)
 {
-    return rb_attr_get(METACLASS_OF(sklass), id_attached) == sklass;
+    return RCLASS_ATTACHED_OBJECT(METACLASS_OF(sklass)) == sklass;
 }
 
 int
 rb_singleton_class_internal_p(VALUE sklass)
 {
-    return (RB_TYPE_P(rb_attr_get(sklass, id_attached), T_CLASS) &&
+    return (RB_TYPE_P(RCLASS_ATTACHED_OBJECT(sklass), T_CLASS) &&
             !rb_singleton_class_has_metaclass_p(sklass));
 }
 
@@ -1677,7 +1675,7 @@ rb_class_attached_object(VALUE klass)
         rb_raise(rb_eTypeError, "`%"PRIsVALUE"' is not a singleton class", klass);
     }
 
-    return rb_attr_get(klass, id_attached);
+    return RCLASS_ATTACHED_OBJECT(klass);
 }
 
 static void
@@ -2206,7 +2204,7 @@ singleton_class_of(VALUE obj)
 
     klass = METACLASS_OF(obj);
     if (!(FL_TEST(klass, FL_SINGLETON) &&
-          rb_attr_get(klass, id_attached) == obj)) {
+          RCLASS_ATTACHED_OBJECT(klass) == obj)) {
         klass = rb_make_metaclass(obj, klass);
     }
 
@@ -2245,7 +2243,7 @@ rb_singleton_class_get(VALUE obj)
     }
     klass = METACLASS_OF(obj);
     if (!FL_TEST(klass, FL_SINGLETON)) return Qnil;
-    if (rb_attr_get(klass, id_attached) != obj) return Qnil;
+    if (RCLASS_ATTACHED_OBJECT(klass) != obj) return Qnil;
     return klass;
 }