remove the dependency on libv8

Gemfile

@@ -4,3 +4,4 @@ source 'http://rubygems.org'
 gemspec
 
 gem 'redjs', :git => 'https://github.com/cowboyd/redjs.git', :tag => 'v0.6.1'
+gem 'libv8', "~> 3.10.8"

ext/v8/build.rb

@@ -0,0 +1,48 @@
+
+LIBV8_COMPATIBILITY = '~> 3.10.8'
+
+def have_rubygem_libv8?
+  gem 'libv8', LIBV8_COMPATIBILITY
+  return true
+rescue Gem::LoadError
+  return false
+end
+
+def build_with_system_libv8
+  dir_config('v8')
+  find_header('v8.h') or begin
+    puts <<-EOS
+    The Ruby Racer requires libv8 #{LIBV8_COMPATIBILITY}
+    to be present on your system in order to compile
+    and link, but it could not be found.
+
+    In order to resolve this, you will either need to manually
+    install an appropriate libv8 and make sure that this
+    build process can find it. If you install it into the
+    standard system path, then it should just be picked up
+    automatically. Otherwise, you'll have to pass some extra
+    flags to the build process as a hint.
+
+    If you don't want to bother with all that, there is a
+    rubygem that will do all this for you. You can add
+    following line to your Gemfile:
+        gem 'libv8', '#{LIBV8_COMPATIBILITY}'
+
+    We hope that helps, and we apologize, but now we have
+    to push the eject button on this install.
+
+    thanks,
+    The Mgmt.
+
+    EOS
+    raise "unable to locate libv8. Please see output for details"
+  end
+  $LDFLAGS << " -lv8_base -lv8_snapshot "
+end
+
+def build_with_rubygem_libv8
+  require 'libv8'
+  include Libv8
+  $INCFLAGS.insert 0, "#{libv8_include_flags} "
+  $LDFLAGS.insert 0, libv8_objects.join(' ') + " "
+end

ext/v8/extconf.rb

@@ -1,31 +1,23 @@
 require 'mkmf'
-begin
-  require 'libv8'
-rescue LoadError
-  require 'rubygems'
-  require 'libv8'
-end
-include Libv8
+require File.expand_path '../build', __FILE__
 
+have_library('pthread')
 have_library('objc') if RUBY_PLATFORM =~ /darwin/
-
-#we have to manually prepend the libv8 include path to INCFLAGS
-#since find_header() does not actually work as advertized.
-#see https://github.com/cowboyd/therubyracer/issues/91
-$INCFLAGS.insert 0, "#{libv8_include_flags} "
 $CPPFLAGS += " -Wall" unless $CPPFLAGS.split.include? "-Wall"
 $CPPFLAGS += " -g" unless $CPPFLAGS.split.include? "-g"
 $CPPFLAGS += " -rdynamic" unless $CPPFLAGS.split.include? "-rdynamic"
 $CPPFLAGS += " -fPIC" unless $CPPFLAGS.split.include? "-rdynamic" or RUBY_PLATFORM =~ /darwin/
 
-$LDFLAGS.insert 0, libv8_objects.join(' ') + " "
-$LIBS << ' -lpthread '
-
-
 CONFIG['LDSHARED'] = '$(CXX) -shared' unless RUBY_PLATFORM =~ /darwin/
 if CONFIG['warnflags']
   CONFIG['warnflags'].gsub!('-Wdeclaration-after-statement', '')
   CONFIG['warnflags'].gsub!('-Wimplicit-function-declaration', '')
 end
 
+if have_rubygem_libv8?
+  build_with_rubygem_libv8
+else
+  build_with_system_libv8
+end
+
 create_makefile('v8/init')

therubyracer.gemspec

@@ -16,8 +16,6 @@ Gem::Specification.new do |gem|
   gem.require_paths = ["lib", "ext"]
   gem.version       = V8::VERSION
 
-  gem.add_dependency "libv8", "~> 3.10.8"
-
   gem.add_development_dependency "rake"
   gem.add_development_dependency "rake-compiler"
   gem.add_development_dependency "gem-compiler"