Use `mrb_immediate_p()` in `mrb_obj_freeze()` and `mrb_obj_frozen()`

src/etc.c

@@ -167,6 +167,7 @@ mrb_word_boxing_float_value(mrb_state *mrb, mrb_float f)
 
   v.value.p = mrb_obj_alloc(mrb, MRB_TT_FLOAT, mrb->float_class);
   v.value.fp->f = f;
+  MRB_SET_FROZEN_FLAG(v.value.bp);
   return v;
 }
 
@@ -177,6 +178,7 @@ mrb_word_boxing_float_pool(mrb_state *mrb, mrb_float f)
   nf->tt = MRB_TT_FLOAT;
   nf->c = mrb->float_class;
   nf->f = f;
+  MRB_SET_FROZEN_FLAG(nf);
   return mrb_obj_value(nf);
 }
 #endif  /* MRB_WITHOUT_FLOAT */

src/kernel.c

@@ -434,24 +434,11 @@ mrb_obj_extend_m(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_obj_freeze(mrb_state *mrb, mrb_value self)
 {
-  struct RBasic *b;
-
-  switch (mrb_type(self)) {
-    case MRB_TT_FALSE:
-    case MRB_TT_TRUE:
-    case MRB_TT_FIXNUM:
-    case MRB_TT_SYMBOL:
-#ifndef MRB_WITHOUT_FLOAT
-    case MRB_TT_FLOAT:
-#endif
-      return self;
-    default:
-      break;
-  }
-
-  b = mrb_basic_ptr(self);
-  if (!MRB_FROZEN_P(b)) {
-    MRB_SET_FROZEN_FLAG(b);
+  if (!mrb_immediate_p(self)) {
+    struct RBasic *b = mrb_basic_ptr(self);
+    if (!MRB_FROZEN_P(b)) {
+      MRB_SET_FROZEN_FLAG(b);
+    }
   }
   return self;
 }
@@ -459,26 +446,7 @@ mrb_obj_freeze(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_obj_frozen(mrb_state *mrb, mrb_value self)
 {
-  struct RBasic *b;
-
-  switch (mrb_type(self)) {
-    case MRB_TT_FALSE:
-    case MRB_TT_TRUE:
-    case MRB_TT_FIXNUM:
-    case MRB_TT_SYMBOL:
-#ifndef MRB_WITHOUT_FLOAT
-    case MRB_TT_FLOAT:
-#endif
-      return mrb_true_value();
-    default:
-      break;
-  }
-
-  b = mrb_basic_ptr(self);
-  if (!MRB_FROZEN_P(b)) {
-    return mrb_false_value();
-  }
-  return mrb_true_value();
+  return mrb_bool_value(mrb_immediate_p(self) || MRB_FROZEN_P(mrb_basic_ptr(self)));
 }
 
 /* 15.3.1.3.15 */

test/t/kernel.rb

@@ -247,6 +247,23 @@ assert('Kernel#freeze') do
   assert_equal obj, obj.freeze
   assert_equal 0, 0.freeze
   assert_equal :a, :a.freeze
+  assert_equal true, true.freeze
+  assert_equal false, false.freeze
+  assert_equal nil, nil.freeze
+  skip unless Object.const_defined?(:Float)
+  assert_equal 0.0, 0.0.freeze
+end
+
+assert('Kernel#frozen?') do
+  assert_false "".frozen?
+  assert_true "".freeze.frozen?
+  assert_true 0.frozen?
+  assert_true :a.frozen?
+  assert_true true.frozen?
+  assert_true false.frozen?
+  assert_true nil.frozen?
+  skip unless Object.const_defined?(:Float)
+  assert_true 0.0.frozen?
 end
 
 assert('Kernel#global_variables', '15.3.1.3.14') do