insns.def: cache nil const

* insns.def (getinlinecache): Qnil is a valid value as a constant.
  this can be observable when accessing a deprecated constant
  which is nil.  non-nil constant is warned just once for each
  location, but every time if it is nil.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62350 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

insns.def

@@ -951,10 +951,13 @@ getinlinecache
 ()
 (VALUE val)
 {
-    val = vm_ic_hit_p(ic, GET_EP());
-    if (val != Qnil) {
+    if (vm_ic_hit_p(ic, GET_EP())) {
+	val = ic->ic_value.value;
 	JUMP(dst);
     }
+    else {
+	val = Qnil;
+    }
 }
 
 /* set inline cache */

test/ruby/test_module.rb

@@ -1429,6 +1429,17 @@ class TestModule < Test::Unit::TestCase
     assert_warn(/deprecated/, bug12382) {c.class_eval "FOO"}
   end
 
+  NIL = nil
+  FALSE = false
+  deprecate_constant(:NIL, :FALSE)
+
+  def test_deprecate_nil_constant
+    w = EnvUtil.verbose_warning {2.times {FALSE}}
+    assert_equal(1, w.scan("::FALSE").size, w)
+    w = EnvUtil.verbose_warning {2.times {NIL}}
+    assert_equal(1, w.scan("::NIL").size, w)
+  end
+
   def test_constants_with_private_constant
     assert_not_include(::TestModule.constants, :PrivateClass)
     assert_not_include(::TestModule.constants(true), :PrivateClass)

vm_insnhelper.c

@@ -3265,16 +3265,13 @@ vm_opt_newarray_min(rb_num_t num, const VALUE *ptr)
 
 #undef id_cmp
 
-static VALUE
+static int
 vm_ic_hit_p(IC ic, const VALUE *reg_ep)
 {
-    if (ic->ic_serial == GET_GLOBAL_CONSTANT_STATE() &&
-	(ic->ic_cref == NULL || ic->ic_cref == rb_vm_get_cref(reg_ep))) {
-	return ic->ic_value.value;
-    }
-    else {
-	return Qnil;
+    if (ic->ic_serial == GET_GLOBAL_CONSTANT_STATE()) {
+	return (ic->ic_cref == NULL || ic->ic_cref == rb_vm_get_cref(reg_ep));
     }
+    return FALSE;
 }
 
 static void