[ruby-dev:39397] redifition warning for module_function

なかだです。

jsonで警告が出ます。

$ ruby -w -rjson -ep
/usr/local/lib/ruby/1.9.1/json/common.rb:273: warning: method redefined; discarding old recurse_proc

最小化すると

$ ruby -w -e 'module M; module_function; def foo;end; module_function :foo; end'
-e:1: warning: method redefined; discarding old foo

module_functionによって定義された特異メソッドをもう一度
module_functionで再定義ということのようです。実際には同じaliasの
ようなものを作り直すだけなので、この警告は不要ではないかと思います。


Index: method.h
===================================================================
--- method.h	(revision 25143)
+++ method.h	(working copy)
@@ -75,4 +75,5 @@ typedef struct rb_method_entry_struct {
 
 #define UNDEFINED_METHOD_ENTRY_P(me) (!(me) || !(me)->def || (me)->def->type == VM_METHOD_TYPE_UNDEF)
+#define CFUNC_EQUAL(cf1, cf2) ((cf1).func == (cf2).func && (cf1).argc == (cf2).argc)
 
 void rb_add_method_cfunc(VALUE klass, ID mid, VALUE (*func)(ANYARGS), int argc, rb_method_flag_t noex);
Index: vm_method.c
===================================================================
--- vm_method.c	(revision 25143)
+++ vm_method.c	(working copy)
@@ -142,4 +142,34 @@ rb_free_method_entry(rb_method_entry_t *
 }
 
+static inline int
+method_definition_equal(const rb_method_definition_t *def1, const rb_method_definition_t *def2)
+{
+    if (def1 == def2) return TRUE;
+    if (!def1 || !def2) return FALSE;
+    if (def1->type != def2->type) return FALSE;
+    if (def1->original_id != def2->original_id) return FALSE;
+    switch (def1->type) {
+      case VM_METHOD_TYPE_CFUNC:
+	if (!CFUNC_EQUAL(def1->body.cfunc, def2->body.cfunc)) return FALSE;
+	break;
+      case VM_METHOD_TYPE_IVAR:
+      case VM_METHOD_TYPE_ATTRSET:
+	if (def1->body.attr_id != def2->body.attr_id) return FALSE;
+	break;
+      case VM_METHOD_TYPE_BMETHOD:
+	if (def1->body.proc != def2->body.proc) return FALSE;
+	break;
+      case VM_METHOD_TYPE_ISEQ:
+	if (def1->body.iseq != def2->body.iseq) return FALSE;
+	break;
+      case VM_METHOD_TYPE_OPTIMIZED:
+	if (def1->body.optimize_type != def2->body.optimize_type) return FALSE;
+	break;
+      default:
+	return FALSE;
+    }
+    return TRUE;
+}
+
 static rb_method_entry_t *
 rb_add_method_def(VALUE klass, ID mid, rb_method_type_t type, rb_method_definition_t *def, rb_method_flag_t noex)
@@ -180,5 +210,5 @@ rb_add_method_def(VALUE klass, ID mid, r
 	rb_method_definition_t *old_def = old_me->def;
 
-	if (old_def == def) return old_me;
+	if (method_definition_equal(old_def, def)) return old_me;
 	rb_vm_check_redefinition_opt_method(old_me);
 
Index: test/ruby/test_class.rb
===================================================================
--- test/ruby/test_class.rb	(revision 25143)
+++ test/ruby/test_class.rb	(working copy)
@@ -99,4 +99,15 @@ class TestClass < Test::Unit::TestCase
   end
 
+  def verbose_warning
+    class << (stderr = "")
+      alias write <<
+    end
+    stderr, $stderr, verbose, $VERBOSE = $stderr, stderr, $VERBOSE, true
+    yield
+  ensure
+    stderr, $stderr, $VERBOSE = $stderr, stderr, verbose
+    return stderr
+  end
+
   def test_module_function
     c = Class.new
@@ -104,4 +115,27 @@ class TestClass < Test::Unit::TestCase
       Module.instance_method(:module_function).bind(c).call(:foo)
     end
+    stderr = verbose_warning do
+      Module.new do
+        def foo; end
+        def foo; end
+      end
+    end
+    assert_match(/method redefined; discarding old foo/, stderr)
+    stderr = verbose_warning do
+      Module.new do
+        def foo; end
+        alias bar foo
+        alias bar foo
+      end
+    end
+    assert_equal("", stderr)
+    stderr = verbose_warning do
+      Module.new do
+        module_function
+        def foo; end
+        module_function :foo
+      end
+    end
+    assert_equal("", stderr)
   end
 


-- 
--- 僕の前にBugはない。
--- 僕の後ろにBugはできる。
    中田 伸悦