$stderr.puts "  building \#{t.name} from \#{t.source}"

		sh "\#{CC} \#{CFLAGS} \#{INCLUDES} -c \#{t.source}"

		$stderr.puts "  linking \#{OBJ.join(', ')} into \#{EXT}"

		sh "\#{LDSHARED} \#{LIBPATH} #{@available.ld_outfile(@extension_name)} \#{OBJ} \#{ADDITIONAL_OBJECTS} \#{LIBS} \#{LIBRUBYARG_SHARED}"

		install EXT, RUBYARCHDIR, :verbose => true

		# Create a new Availability instance.

		#

		# Valid keys for the options hash include:

		# * <tt>:loaded_libs</tt> -- libraries to load by default

		# * <tt>:library_paths</tt> -- libraries paths to include by default

		# * <tt>:headers</tt> -- headers to load by default

		# * <tt>:compiler</tt> -- which compiler to use when determining availability

		# * <tt>:includes</tt> -- directories that should be searched for include files

		def initialize(options = {})      

			@loaded_libs = options[:loaded_libs] || []

			@loaded_libs.flatten!

			@library_paths = [(options[:library_paths] || [])].flatten

			# Not sure what COMMON_HEADERS looks like when populated

			@headers = options[:headers] || [] # Config::CONFIG["COMMON_HEADERS"]

			@compiler = options[:compiler] || Config::CONFIG["CC"]

			@includes = [(options[:includes] || DEFAULT_INCLUDES)].flatten

			@logger = Logger.new('mkrf.log')

			@defines = []

		end

		def can_link?( function_body )

			silence_command_line do

				create_source(function_body)

				cmd = link_command()

				@logger.debug "Running link command: #{cmd}"

				system( cmd )

			end

		ensure

			FileUtils.rm_f TEMP_SOURCE_FILE

			FileUtils.rm_f TEMP_EXECUTABLE

		end

		# Add the LIBRUBYARG_SHARED setting to the library paths for non-windows boxen. This is

		# necessary if Ruby is installed in a directory that isn't in the default library

		# search path (e.g., on FreeBSD where Ruby is /usr/local/bin/ruby).

		def library_paths_compile_string

			if RUBY_PLATFORM =~ /mswin/

				@library_paths.collect {|l| "/libpath:#{l}"}.join(' ')

			else

				Config::CONFIG['LIBRUBYARG_SHARED'] + @library_paths.collect {|l| "-L#{l}"}.join(' ')

			end

		end

		# Separate includes with a newline instead of a literal '\n'

		def header_include_string

			@headers.collect {|header| "#include <#{header}>"}.join( "\n" )

		end

		# Log the created source to the logfile

		def create_source( src )

			@logger.debug "Creating source file:\n#{src}"

			File.open( TEMP_SOURCE_FILE, "w+" ) do |f|

				f.write( src )

			end

		end

		# Prepend the LIBS string directly to the @loaded_libs, as not all arguments in

		# it 

		def library_compile_string

			added_libs = nil

			if RUBY_PLATFORM =~ /mswin/

				added_libs = @loaded_libs.join(' ')

			else

				added_libs = @loaded_libs.collect {|l| "-l#{l}"}.join(' ')

			end

			return Config::CONFIG["LIBS"] + ' ' + added_libs

		end

		# Redirect to the mkrf log instead of /dev/null