# File lib/mkmf.rb, line 1189
def create_makefile(target, srcprefix = nil)
  $target = target
  libpath = $DEFLIBPATH|$LIBPATH
  message "creating Makefile\n"
  rm_f "conftest*"
  if CONFIG["DLEXT"] == $OBJEXT
    for lib in libs = $libs.split
      lib.sub!(/-l(.*)/, %%"lib\\1.#{$LIBEXT}"%)
    end
    $defs.push(format("-DEXTLIB='%s'", libs.join(",")))
  end

  if target.include?('/')
    target_prefix, target = File.split(target)
    target_prefix[0,0] = '/'
  else
    target_prefix = ""
  end

  srcprefix ||= '$(srcdir)'
  Config::expand(srcdir = srcprefix.dup)

  if not $objs
    $objs = []
    srcs = Dir[File.join(srcdir, "*.{#{SRC_EXT.join(%q{,})}}")]
    for f in srcs
      obj = File.basename(f, ".*") << ".o"
      $objs.push(obj) unless $objs.index(obj)
    end
  elsif !(srcs = $srcs)
    srcs = $objs.collect {|obj| obj.sub(/\.o\z/, '.c')}
  end
  $srcs = srcs
  for i in $objs
    i.sub!(/\.o\z/, ".#{$OBJEXT}")
  end
  $objs = $objs.join(" ")

  target = nil if $objs == ""

  if target and EXPORT_PREFIX
    if File.exist?(File.join(srcdir, target + '.def'))
      deffile = "$(srcdir)/$(TARGET).def"
      unless EXPORT_PREFIX.empty?
        makedef = %{-pe "sub!(/^(?=\\w)/,'#{EXPORT_PREFIX}') unless 1../^EXPORTS$/i"}
      end
    else
      makedef = %{-e "puts 'EXPORTS', '#{EXPORT_PREFIX}Init_$(TARGET)'"}
    end
    if makedef
      $distcleanfiles << '$(DEFFILE)'
      origdef = deffile
      deffile = "$(TARGET)-$(arch).def"
    end
  end
  origdef ||= ''

  libpath = libpathflag(libpath)

  dllib = target ? "$(TARGET).#{CONFIG['DLEXT']}" : ""
  staticlib = target ? "$(TARGET).#$LIBEXT" : ""
  mfile = open("Makefile", "wb")
  mfile.print configuration(srcprefix)
  mfile.print "
libpath = #{($DEFLIBPATH|$LIBPATH).join(" ")}
LIBPATH = #{libpath}
DEFFILE = #{deffile}

CLEANFILES = #{$cleanfiles.join(' ')}
DISTCLEANFILES = #{$distcleanfiles.join(' ')}

extout = #{$extout}
extout_prefix = #{$extout_prefix}
target_prefix = #{target_prefix}
LOCAL_LIBS = #{$LOCAL_LIBS}
LIBS = #{$LIBRUBYARG} #{$libs} #{$LIBS}
SRCS = #{srcs.collect(&File.method(:basename)).join(' ')}
OBJS = #{$objs}
TARGET = #{target}
DLLIB = #{dllib}
EXTSTATIC = #{$static || ""}
STATIC_LIB = #{staticlib unless $static.nil?}
#{!$extout && defined?($installed_list) ? "INSTALLED_LIST = #{$installed_list}\n" : ""}
"
  install_dirs.each {|d| mfile.print("%-14s= %s\n" % d) if /^[[:upper:]]/ =~ d[0]}
  n = ($extout ? '$(RUBYARCHDIR)/' : '') + '$(TARGET).'
  mfile.print "
TARGET_SO     = #{($extout ? '$(RUBYARCHDIR)/' : '')}$(DLLIB)
CLEANLIBS     = #{n}#{CONFIG['DLEXT']} #{n}il? #{n}tds #{n}map
CLEANOBJS     = *.#{$OBJEXT} *.#{$LIBEXT} *.s[ol] *.pdb *.exp *.bak

all:            #{$extout ? "install" : target ? "$(DLLIB)" : "Makefile"}
static:         $(STATIC_LIB)#{$extout ? " install-rb" : ""}
"
  mfile.print CLEANINGS
  dirs = []
  mfile.print "install: install-so install-rb\n\n"
  sodir = (dir = "$(RUBYARCHDIR)").dup
  mfile.print("install-so: #{dir}\n")
  if target
    f = "$(DLLIB)"
    dest = "#{dir}/#{f}"
    mfile.print "install-so: #{dest}\n"
    unless $extout
      mfile.print "#{dest}: #{f}\n"
      if (sep = config_string('BUILD_FILE_SEPARATOR'))
        f.gsub!("/", sep)
        dir.gsub!("/", sep)
        sep = ":/="+sep
        f.gsub!(/(\$\(\w+)(\))/) {$1+sep+$2}
        f.gsub!(/(\$\{\w+)(\})/) {$1+sep+$2}
        dir.gsub!(/(\$\(\w+)(\))/) {$1+sep+$2}
        dir.gsub!(/(\$\{\w+)(\})/) {$1+sep+$2}
      end
      mfile.print "\t$(INSTALL_PROG) #{f} #{dir}\n"
      if defined?($installed_list)
        mfile.print "\t@echo #{dir}/#{File.basename(f)}>>$(INSTALLED_LIST)\n"
      end
    end
  end
  mfile.print("install-rb: pre-install-rb install-rb-default\n")
  mfile.print("install-rb-default: pre-install-rb-default\n")
  mfile.print("pre-install-rb: Makefile\n")
  mfile.print("pre-install-rb-default: Makefile\n")
  for sfx, i in [["-default", [["lib/**/*.rb", "$(RUBYLIBDIR)", "lib"]]], ["", $INSTALLFILES]]
    files = install_files(mfile, i, nil, srcprefix) or next
    for dir, *files in files
      unless dirs.include?(dir)
        dirs << dir
        mfile.print "pre-install-rb#{sfx}: #{dir}\n"
      end
      files.each do |f|
        dest = "#{dir}/#{File.basename(f)}"
        mfile.print("install-rb#{sfx}: #{dest}\n")
        mfile.print("#{dest}: #{f}\n\t$(#{$extout ? 'COPY' : 'INSTALL_DATA'}) ")
        sep = config_string('BUILD_FILE_SEPARATOR')
        if sep
          f = f.gsub("/", sep)
          sep = ":/="+sep
          f = f.gsub(/(\$\(\w+)(\))/) {$1+sep+$2}
          f = f.gsub(/(\$\{\w+)(\})/) {$1+sep+$2}
        else
          sep = ""
        end
        mfile.print("#{f} $(@D#{sep})\n")
        if defined?($installed_list) and !$extout
          mfile.print("\t@echo #{dest}>>$(INSTALLED_LIST)\n")
        end
      end
    end
  end
  dirs.unshift(sodir) if target and !dirs.include?(sodir)
  dirs.each {|dir| mfile.print "#{dir}:\n\t$(MAKEDIRS) $@\n"}

  mfile.print "\nsite-install: site-install-so site-install-rb\nsite-install-so: install-so\nsite-install-rb: install-rb\n\n"

  return unless target

  mfile.puts SRC_EXT.collect {|ext| ".path.#{ext} = $(VPATH)"} if $nmake == ?b
  mfile.print ".SUFFIXES: .#{SRC_EXT.join(' .')} .#{$OBJEXT}\n"
  mfile.print "\n"

  CXX_EXT.each do |ext|
    COMPILE_RULES.each do |rule|
      mfile.printf(rule, ext, $OBJEXT)
      mfile.printf("\n\t%s\n\n", COMPILE_CXX)
    end
  end
  %w[c].each do |ext|
    COMPILE_RULES.each do |rule|
      mfile.printf(rule, ext, $OBJEXT)
      mfile.printf("\n\t%s\n\n", COMPILE_C)
    end
  end

  mfile.print "$(RUBYARCHDIR)/" if $extout
  mfile.print "$(DLLIB): "
  mfile.print "$(DEFFILE) " if makedef
  mfile.print "$(OBJS) Makefile\n"
  mfile.print "\t@-$(RM) $@\n"
  mfile.print "\t@-$(MAKEDIRS) $(@D)\n" if $extout
  link_so = LINK_SO.gsub(/^/, "\t")
  mfile.print link_so, "\n\n"
  unless $static.nil?
    mfile.print "$(STATIC_LIB): $(OBJS)\n\t"
    mfile.print "$(AR) #{config_string('ARFLAGS') || 'cru '}$@ $(OBJS)"
    config_string('RANLIB') do |ranlib|
      mfile.print "\n\t@-#{ranlib} $(DLLIB) 2> /dev/null || true"
    end
  end
  mfile.print "\n\n"
  if makedef
    mfile.print "$(DEFFILE): #{origdef}\n"
    mfile.print "\t$(RUBY) #{makedef} #{origdef} > $@\n\n"
  end

  depend = File.join(srcdir, "depend")
  if File.exist?(depend)
    suffixes = []
    depout = []
    open(depend, "r") do |dfile|
      mfile.printf "###\n"
      cont = implicit = nil
      impconv = proc do
        COMPILE_RULES.each {|rule| depout << (rule % implicit[0]) << implicit[1]}
        implicit = nil
      end
      ruleconv = proc do |line|
        if implicit
          if /\A\t/ =~ line
            implicit[1] << line
            next
          else
            impconv[]
          end
        end
        if m = /\A\.(\w+)\.(\w+)(?:\s*:)/.match(line)
          suffixes << m[1] << m[2]
          implicit = [[m[1], m[2]], [m.post_match]]
          next
        elsif RULE_SUBST and /\A(?!\s*\w+\s*=)[$\w][^#]*:/ =~ line
          line.gsub!(%r"(\s)(?!\.)([^$(){}+=:\s\/\\,]+)(?=\s|\z)") {$1 + RULE_SUBST % $2}
        end
        depout << line
      end
      while line = dfile.gets()
        line.gsub!(/\.o\b/, ".#{$OBJEXT}")
        line.gsub!(/\$\(hdrdir\)\/config.h/, $config_h) if $config_h
        if /(?:^|[^\\])(?:\\\\)*\\$/ =~ line
          (cont ||= []) << line
          next
        elsif cont
          line = (cont << line).join
          cont = nil
        end
        ruleconv.call(line)
      end
      if cont
        ruleconv.call(cont.join)
      elsif implicit
        impconv.call
      end
    end
    unless suffixes.empty?
      mfile.print ".SUFFIXES: .", suffixes.uniq.join(" ."), "\n\n"
    end
    mfile.print "$(OBJS): $(RUBY_EXTCONF_H)\n\n" if $extconf_h
    mfile.print depout
  else
    headers = %w[ruby.h defines.h]
    if RULE_SUBST
      headers.each {|h| h.sub!(/.*/) {|*m| RULE_SUBST % m}}
    end
    headers << $config_h if $config_h
    headers << "$(RUBY_EXTCONF_H)" if $extconf_h
    mfile.print "$(OBJS): ", headers.join(' '), "\n"
  end

  $makefile_created = true
ensure
  mfile.close if mfile
end