variable.c: real class name

* variable.c (rb_class2name): should return real class name, not
  singleton class or iclass.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43367 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/-test-/class/class2name.c

@@ -0,0 +1,14 @@
+#include <ruby/ruby.h>
+
+static VALUE
+class2name(VALUE self, VALUE klass)
+{
+    const char *name = rb_class2name(klass);
+    return name ? rb_str_new_cstr(name) : Qnil;
+}
+
+void
+Init_class2name(VALUE klass)
+{
+    rb_define_singleton_method(klass, "class2name", class2name, 1);
+}

ext/-test-/class/extconf.rb

@@ -0,0 +1,7 @@
+$INCFLAGS << " -I$(topdir) -I$(top_srcdir)"
+$srcs = Dir[File.join($srcdir, "*.{#{SRC_EXT.join(%q{,})}}")]
+inits = $srcs.map {|s| File.basename(s, ".*")}
+inits.delete("init")
+inits.map! {|s|"X(#{s})"}
+$defs << "-DTEST_INIT_FUNCS(X)=\"#{inits.join(' ')}\""
+create_makefile("-test-/class")

ext/-test-/class/init.c

@@ -0,0 +1,11 @@
+#include "ruby.h"
+
+#define init(n) {void Init_##n(VALUE mod); Init_##n(mod);}
+
+void
+Init_class(void)
+{
+    VALUE mBug = rb_define_module("Bug");
+    VALUE mod = rb_define_module_under(mBug, "Class");
+    TEST_INIT_FUNCS(init);
+}