Add pluggable versioning by mruby-version

mrbgems/default.gembox

@@ -58,4 +58,7 @@ MRuby::GemBox.new do |conf|
 
   # Generate mruby command
   conf.gem :core => "mruby-bin-mruby"
+
+  # Use mruby verison 
+  conf.gem :core => "mruby-version"
 end

mrbgems/mruby-version/mrbgem.rake

+MRuby::Gem::Specification.new('mruby-version') do |spec|
+  spec.license = 'MIT'
+  spec.author  = 'mruby developers'
+end

mrbgems/mruby-version/mrblib/version.rb

+module Kernel
+  def show_version
+    "mruby " + MRUBY_VERSION + " (" + MRUBY_RELEASE_DATE + ")\n"
+  end
+end

mrbgems/mruby-version/src/version.c

+#include "mruby.h"
+#include "mruby/variable.h"
+#include "version.h"
+
+void
+mrb_mruby_version_gem_init(mrb_state* mrb)
+{
+  mrb_define_global_const(mrb, "MRUBY_VERSION", mrb_str_new_cstr(mrb, MRUBY_VERSION));
+  mrb_define_global_const(mrb, "MRUBY_RELEASE_DATE", mrb_str_new_cstr(mrb, MRUBY_RELEASE_DATE));
+}
+
+void
+mrb_mruby_version_gem_final(mrb_state* mrb)
+{
+}
+

mrbgems/mruby-version/src/version.h

+#define MRUBY_VERSION "v1.0.0"
+#define MRUBY_PATCHLEVEL 0
+#define MRUBY_REVISION 0
+
+#define MRUBY_RELEASE_DATE "2014-01-31"
+#define MRUBY_RELEASE_YEAR 2014
+#define MRUBY_RELEASE_MONTH 1
+#define MRUBY_RELEASE_DAY 31
+

src/print.c

@@ -6,6 +6,7 @@
 
 #include "mruby.h"
 #include "mruby/string.h"
+#include "mruby/variable.h"
 
 static void
 printstr(mrb_state *mrb, mrb_value obj)
@@ -56,7 +57,12 @@ mrb_show_version(mrb_state *mrb)
   static const char version_msg[] = "mruby - Embeddable Ruby  Copyright (c) 2010-2014 mruby developers\n";
   mrb_value msg;
 
-  msg = mrb_str_new(mrb, version_msg, sizeof(version_msg) - 1);
+  if (mrb_const_defined(mrb, mrb_obj_value(mrb->object_class), mrb_intern_lit(mrb, "MRUBY_VERSION"))) {
+    msg = mrb_funcall(mrb, mrb_obj_value(mrb->kernel_module), "show_version", 0);
+  }
+  else {
+    msg = mrb_str_new(mrb, version_msg, sizeof(version_msg) - 1);
+  }
   printstr(mrb, msg);
 }