method in instance_eval

* class.c (rb_special_singleton_class_of): utility function.
* vm_eval.c (eval_under): special deal for class variable scope with
  instance_eval.
* vm_eval.c (rb_obj_instance_eval, rb_obj_instance_exec): allow method
  definition in instance_eval of special constants.  [ruby-core:28324]
  [Bug #2788]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36647 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 19 insertions, 5 deletions

diff --git a/class.c b/class.c
index 4acdc0807d..2ee5b8867a 100644
--- a/class.c
+++ b/class.c
@@ -1286,6 +1286,20 @@ rb_undef_method(VALUE klass, const char *name)
     }\
 } while (0)
 
+static inline VALUE
+special_singleton_class_of(VALUE obj)
+{
+    SPECIAL_SINGLETON(Qnil, rb_cNilClass);
+    SPECIAL_SINGLETON(Qfalse, rb_cFalseClass);
+    SPECIAL_SINGLETON(Qtrue, rb_cTrueClass);
+    return Qnil;
+}
+
+VALUE
+rb_special_singleton_class(VALUE obj)
+{
+    return special_singleton_class_of(obj);
+}
 
 /*!
  * \internal
@@ -1304,11 +1318,11 @@ singleton_class_of(VALUE obj)
     if (FIXNUM_P(obj) || SYMBOL_P(obj)) {
 	rb_raise(rb_eTypeError, "can't define singleton");
     }
-    if (rb_special_const_p(obj)) {
-	SPECIAL_SINGLETON(Qnil, rb_cNilClass);
-	SPECIAL_SINGLETON(Qfalse, rb_cFalseClass);
-	SPECIAL_SINGLETON(Qtrue, rb_cTrueClass);
-	rb_bug("unknown immediate %p", (void *)obj);
+    if (SPECIAL_CONST_P(obj)) {
+	klass = special_singleton_class_of(obj);
+	if (NIL_P(klass))
+	    rb_bug("unknown immediate %p", (void *)obj);
+	return klass;
     }
 
     if (FL_TEST(RBASIC(obj)->klass, FL_SINGLETON) &&