# File lib/mkmf.rb, line 1068
def configuration(srcdir)
  mk = []
  vpath = %w[$(srcdir) $(topdir) $(hdrdir)]
  if !CROSS_COMPILING
    case CONFIG['build_os']
    when 'cygwin'
      if CONFIG['target_os'] != 'cygwin'
        vpath.each {|p| p.sub!(/.*/, '$(shell cygpath -u \&)')}
      end
    when 'msdosdjgpp'
      CONFIG['PATH_SEPARATOR'] = ';'
    end
  end
  mk << %{
SHELL = /bin/sh

#### Start of system configuration section. ####

srcdir = #{srcdir.gsub(/\$\((srcdir)\)|\$\{(srcdir)\}/) {mkintpath(CONFIG[$1||$2])}.quote}
topdir = #{mkintpath($extmk ? CONFIG["topdir"] : $topdir).quote}
hdrdir = #{$extmk ? mkintpath(CONFIG["hdrdir"]).quote : '$(topdir)'}
VPATH = #{vpath.join(CONFIG['PATH_SEPARATOR'])}
}
  if $extmk
    mk << "RUBYLIB = -\nRUBYOPT = -rpurelib.rb\n"
  end
  if destdir = CONFIG["prefix"][$dest_prefix_pattern, 1]
    mk << "\nDESTDIR = #{destdir}\n"
  end
  CONFIG.each do |key, var|
    next unless /prefix$/ =~ key
    mk << "#{key} = #{with_destdir(var)}\n"
  end
  CONFIG.each do |key, var|
    next if /^abs_/ =~ key
    next unless /^(?:src|top|hdr|(.*))dir$/ =~ key and $1
    mk << "#{key} = #{with_destdir(var)}\n"
  end
  if !$extmk and !$configure_args.has_key?('--ruby') and
      sep = config_string('BUILD_FILE_SEPARATOR')
    sep = ":/=#{sep}"
  else
    sep = ""
  end
  extconf_h = $extconf_h ? "-DRUBY_EXTCONF_H=\\\"$(RUBY_EXTCONF_H)\\\" " : $defs.join(" ")<<" "
  mk << %{
CC = #{CONFIG['CC']}
LIBRUBY = #{CONFIG['LIBRUBY']}
LIBRUBY_A = #{CONFIG['LIBRUBY_A']}
LIBRUBYARG_SHARED = #$LIBRUBYARG_SHARED
LIBRUBYARG_STATIC = #$LIBRUBYARG_STATIC

RUBY_EXTCONF_H = #{$extconf_h}
CFLAGS   = #{$static ? '' : CONFIG['CCDLFLAGS']} #$CFLAGS #$ARCH_FLAG
INCFLAGS = -I. #$INCFLAGS
DEFS     = #{CONFIG['DEFS']}
CPPFLAGS = #{extconf_h}#{$CPPFLAGS}
CXXFLAGS = $(CFLAGS) #{CONFIG['CXXFLAGS']}
DLDFLAGS = #$LDFLAGS #$DLDFLAGS #$ARCH_FLAG
LDSHARED = #{CONFIG['LDSHARED']}
AR = #{CONFIG['AR']}
EXEEXT = #{CONFIG['EXEEXT']}

RUBY_INSTALL_NAME = #{CONFIG['RUBY_INSTALL_NAME']}
RUBY_SO_NAME = #{CONFIG['RUBY_SO_NAME']}
arch = #{CONFIG['arch']}
sitearch = #{CONFIG['sitearch']}
ruby_version = #{Config::CONFIG['ruby_version']}
ruby = #{$ruby}
RUBY = $(ruby#{sep})
RM = #{config_string('RM') || '$(RUBY) -run -e rm -- -f'}
MAKEDIRS = #{config_string('MAKEDIRS') || '@$(RUBY) -run -e mkdir -- -p'}
INSTALL = #{config_string('INSTALL') || '@$(RUBY) -run -e install -- -vp'}
INSTALL_PROG = #{config_string('INSTALL_PROG') || '$(INSTALL) -m 0755'}
INSTALL_DATA = #{config_string('INSTALL_DATA') || '$(INSTALL) -m 0644'}
COPY = #{config_string('CP') || '@$(RUBY) -run -e cp -- -v'}

#### End of system configuration section. ####

preload = #{$preload ? $preload.join(' ') : ''}
}
  if $nmake == ?b
    mk.each do |x|
      x.gsub!(/^(MAKEDIRS|INSTALL_(?:PROG|DATA))+\s*=.*\n/) do
        "!ifndef " + $1 + "\n" +
        $& +
        "!endif\n"
      end
    end
  end
  mk
end