extlibs.rb: add --cache option

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53599 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Wed Jan 20 17:13:39 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+
+
 Tue Jan 19 17:03:40 2016  Martin Duerst  <duerst@it.aoyama.ac.jp>
 
 	* common.mk: Added Unicode data file CaseFolding.txt to be additionally

tool/extlibs.rb

@@ -3,9 +3,6 @@ require 'fileutils'
 require 'digest'
 require_relative 'downloader'
 
-cache_dir = ".downloaded-cache"
-FileUtils.mkdir_p(cache_dir)
-
 def do_download(url, base, cache_dir)
   Downloader.download(url, base, cache_dir, nil)
 end
@@ -74,22 +71,35 @@ def do_patch(dest, patch, args)
   $?.success? or raise "failed to patch #{patch}"
 end
 
+cache_dir = ENV['CACHE_DIR'] || ".downloaded-cache"
+mode = :all
+until ARGV.empty?
   case ARGV[0]
   when '--download'
     mode = :download
-  ARGV.shift
   when '--extract'
     mode = :extract
-  ARGV.shift
   when '--patch'
     mode = :patch
-  ARGV.shift
   when '--all'
     mode = :all
+  when '--cache'
     ARGV.shift
+    cache_dir = ARGV[0]
+  when /\A--cache=/
+    cache_dir = $'
+  when '--'
+    ARGV.shift
+    break
+  when /\A-/
+    abort "unknown option: #{ARGV[0]}"
   else
-  mode = :all
+    break
   end
+  ARGV.shift
+end
+
+FileUtils.mkdir_p(cache_dir)
 
 success = true
 ARGV.each do |dir|