# class Gem::Ext::ExtConfBuilder

### Public Class Methods

build(extension, dest_path, results, args=[], lib_dir=nil) click to toggle source

    # File lib/rubygems/ext/ext_conf_builder.rb, line 15
    def self.build(extension, dest_path, results, args=[], lib_dir=nil)
      tmp_dest = Dir.mktmpdir(".gem.", ".")

      # Some versions of `mktmpdir` return absolute paths, which will break make
      # if the paths contain spaces. However, on Ruby 1.9.x on Windows, relative
      # paths cause all C extension builds to fail.
      #
      # As such, we convert to a relative path unless we are using Ruby 1.9.x on
      # Windows. This means that when using Ruby 1.9.x on Windows, paths with
      # spaces do not work.
      #
      # Details: https://github.com/rubygems/rubygems/issues/977#issuecomment-171544940
      tmp_dest = get_relative_path(tmp_dest)

      Tempfile.open %w"siteconf .rb", "." do |siteconf|
        siteconf.puts "require 'rbconfig'"
        siteconf.puts "dest_path = #{tmp_dest.dump}"
        %w[sitearchdir sitelibdir].each do |dir|
          siteconf.puts "RbConfig::MAKEFILE_CONFIG['#{dir}'] = dest_path"
          siteconf.puts "RbConfig::CONFIG['#{dir}'] = dest_path"
        end

        siteconf.close

        destdir = ENV["DESTDIR"]

        begin
          cmd = Gem.ruby.shellsplit << "-I" << File.expand_path("../../..", __FILE__) <<
                "-r" << get_relative_path(siteconf.path) << File.basename(extension)
          cmd.push(*args)

          begin
            run cmd, results
          ensure
            if File.exist? 'mkmf.log'
              unless $?.success?
                results << "To see why this extension failed to compile, please check" \
                  " the mkmf.log which can be found here:\n"
                results << "  " + File.join(dest_path, 'mkmf.log') + "\n"
              end
              FileUtils.mv 'mkmf.log', dest_path
            end
            siteconf.unlink
          end

          ENV["DESTDIR"] = nil

          make dest_path, results

          if tmp_dest
            # TODO remove in RubyGems 3
            if Gem.install_extension_in_lib and lib_dir
              FileUtils.mkdir_p lib_dir
              entries = Dir.entries(tmp_dest) - %w[. ..]
              entries = entries.map { |entry| File.join tmp_dest, entry }
              FileUtils.cp_r entries, lib_dir, :remove_destination => true
            end

            FileEntry.new(tmp_dest).traverse do |ent|
              destent = ent.class.new(dest_path, ent.rel)
              destent.exist? or FileUtils.mv(ent.path, destent.path)
            end
          end
        ensure
          ENV["DESTDIR"] = destdir
          siteconf.close!
        end
      end

      results
    ensure
      FileUtils.rm_rf tmp_dest if tmp_dest
    end

### Private Class Methods

get_relative_path(path) click to toggle source

    # File lib/rubygems/ext/ext_conf_builder.rb, line 90
    def self.get_relative_path(path)
      path[0..Dir.pwd.length-1] = '.' if path.start_with?(Dir.pwd)
      path
    end