diff --git a/ChangeLog b/ChangeLog
index ba1676b35f..1e56054594 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,4 @@
-Sun Feb  6 23:50:36 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Mon Feb  7 00:13:38 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/socket/extconf.rb: check if getaddrinfo() works fine only when
 	  wide-getaddrinfo option is not given.  fixed: [ruby-dev:25422]
@@ -19,6 +19,9 @@ Sun Feb  6 23:50:36 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 	* lib/mkmf.rb (dir_config): accept arrays of directory names as
 	  default values.
 
+	* mkconfig.rb: no longer embed srcdir and compile_dir into
+	  rbconfig.rb.
+
 Sun Feb  6 19:23:01 2005  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* eval.c (stack_extend): add prototype because VC++8 doesn't
diff --git a/ext/extmk.rb b/ext/extmk.rb
index 62d1cf75af..88f5028a39 100644
--- a/ext/extmk.rb
+++ b/ext/extmk.rb
@@ -36,6 +36,14 @@ def sysquote(x)
   @quote ? x.quote : x
 end
 
+def relative_from(path, base)
+  if File.expand_path(path) == File.expand_path(path, base)
+    path
+  else
+    File.join(base, path)
+  end
+end
+
 def extmake(target)
   print "#{$message} #{target}\n"
   $stdout.flush
@@ -58,9 +66,7 @@ def extmake(target)
     top_srcdir = $top_srcdir
     topdir = $topdir
     prefix = "../" * (target.count("/")+1)
-    if File.expand_path(top_srcdir) != File.expand_path(top_srcdir, dir)
-      $hdrdir = $top_srcdir = prefix + top_srcdir
-    end
+    $hdrdir = $top_srcdir = relative_from(top_srcdir, prefix)
     $topdir = prefix + $topdir
     $target = target
     $mdir = target
@@ -228,10 +234,7 @@ dir = Dir.pwd
 FileUtils::makedirs('ext')
 Dir::chdir('ext')
 
-if File.expand_path(srcdir) != File.expand_path(srcdir, dir)
-  $hdrdir = $top_srcdir = "../" + srcdir
-end
-$topdir = ".."
+$hdrdir = $top_srcdir = relative_from(srcdir, $topdir = "..")
 ext_prefix = "#{$top_srcdir}/ext"
 Dir.glob("#{ext_prefix}/*/**/extconf.rb") do |d|
   d = File.dirname(d)
@@ -295,7 +298,7 @@ SRC
 end
 rubies = []
 %w[RUBY RUBYW].each {|r|
-  config_string(r+"_INSTALL_NAME") {|r| rubies << r+EXEEXT}
+  config_string(r+"_INSTALL_NAME", Config::CONFIG) {|r| rubies << r+EXEEXT}
 }
 
 Dir.chdir ".."
diff --git a/mkconfig.rb b/mkconfig.rb
index b0abee35ad..e743aa803d 100644
--- a/mkconfig.rb
+++ b/mkconfig.rb
@@ -1,16 +1,19 @@
 #!./miniruby -s
 
 # avoid warnings with -d.
-$srcdir ||= nil
 $install_name ||= nil
 $so_name ||= nil
 
-require File.dirname($0)+"/lib/ftools"
+srcdir = File.dirname(__FILE__)
+$:.replace [srcdir+"/lib", "."]
+
+require "fileutils"
 mkconfig = File.basename($0)
 
 rbconfig_rb = ARGV[0] || 'rbconfig.rb'
-srcdir = $srcdir || '.'
-File.makedirs(File.dirname(rbconfig_rb), true)
+unless File.directory?(dir = File.dirname(rbconfig_rb))
+  FileUtils.makedirs(dir, :verbose => true)
+end
 
 version = RUBY_VERSION
 rbconfig_rb_tmp = rbconfig_rb + '.tmp'
@@ -52,17 +55,12 @@ File.foreach "config.status" do |line|
       v_others << v
     end
     has_version = true if name == "MAJOR"
-  elsif /^(?:ac_given_)?srcdir=(.*)/ =~ line
-    srcdir = $1.strip
   elsif /^ac_given_INSTALL=(.*)/ =~ line
     v_fast << "  CONFIG[\"INSTALL\"] = " + $1 + "\n"
   end
 #  break if /^CEOF/
 end
 
-srcdir = File.expand_path(srcdir)
-v_fast.unshift("  CONFIG[\"srcdir\"] = \"" + srcdir + "\"\n")
-
 v_fast.collect! do |x|
   if /"prefix"/ === x
     x.sub(/= (.*)/, '= (TOPDIR || DESTDIR + \1)')
@@ -111,7 +109,7 @@ print <<EOS
   CONFIG["archdir"] = "$(rubylibdir)/$(arch)"
   CONFIG["sitelibdir"] = "$(sitedir)/$(ruby_version)"
   CONFIG["sitearchdir"] = "$(sitelibdir)/$(sitearch)"
-  CONFIG["compile_dir"] = "#{Dir.pwd}"
+  CONFIG["topdir"] = File.dirname(__FILE__)
   MAKEFILE_CONFIG = {}
   CONFIG.each{|k,v| MAKEFILE_CONFIG[k] = v.dup}
   def Config::expand(val, config = CONFIG)
@@ -137,6 +135,17 @@ EOS
 $stdout.flush
 $stdout.reopen($orgout)
 config.close
-File.rename(rbconfig_rb_tmp, rbconfig_rb)
+if $timestamp and
+   File.exist?(rbconfig_rb) and
+   FileUtils.compare_file(rbconfig_rb, rbconfig_rb_tmp)
+  puts "#{rbconfig_rb} unchanged"
+  File.unlink(rbconfig_rb_tmp)
+else
+  puts "#{rbconfig_rb} updated"
+  File.rename(rbconfig_rb_tmp, rbconfig_rb)
+end
+if String === $timestamp
+  FileUtils.touch($timestamp)
+end
 
 # vi:set sw=2: