common.mk: extract-gems

* common.mk (extract-gems): extract gem files to install them even
  if zlib is not available.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49271 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

common.mk

@@ -924,6 +924,14 @@ update-gems: PHONY
 	    -e 'File.unlink(*(old-[gem]))' \
 	    bundled_gems
 
+extract-gems: PHONY
+	$(ECHO) Extracting bundled gem files...
+	$(Q) $(RUNRUBY) -C "$(srcdir)/gems" \
+	    -I../tool -rgem-unpack -answ \
+	    -e 'gem, ver = *$$F' \
+	    -e 'Gem.unpack("#{gem}-#{ver}.gem")' \
+	    bundled_gems
+
 UPDATE_LIBRARIES = no
 
 ### set the following environment variable or uncomment the line if
@@ -973,6 +981,9 @@ extract-extlibs:
 clean-extlibs:
 	$(Q) $(RMALL) $(srcdir)/.downloaded-cache
 
+clean-gems:
+	$(Q) $(RM) gems/*.gem
+
 CLEAN_CACHE = clean-extlibs
 
 info: info-program info-libruby_a info-libruby_so info-arch

tool/gem-unpack.rb

@@ -0,0 +1,16 @@
+require 'rubygems'
+require 'rubygems/package'
+
+def Gem.unpack(file, dir = nil)
+  pkg = Gem::Package.new(file)
+  pkg.security_policy = Gem::Security::LowSecurity
+  spec = pkg.spec
+  target = spec.full_name
+  target = File.join(dir, target) if dir
+  pkg.extract_files target
+  spec_file = File.join(target, "#{spec.name}.gemspec")
+  open(spec_file, 'wb') do |f|
+    f.print spec.to_ruby
+  end
+  puts "Unpacked #{file}"
+end