Toolchain for building mruby with emscripten

build_config.rb

# Sample usage
MRuby::CrossBuild.new('emscripten') do |conf|
  toolchain :emscripten
  # conf.gem :github => 'mattn/mruby-onig-regexp'
  # conf.gem :github => 'take-cheeze/mruby-marshal'
  conf.gembox 'default'

   conf.cc do |cc|
     cc.flags = [ENV['CFLAGS'] || %w()]
     cc.compile_options = "%{flags} -O3 -MMD -o %{outfile} -c %{infile} -I$HOME/dev/onig/src"
     # cc.defines = %w(MRB_INTEGER_DIVISION)
   end

   # conf.cxx.defines = %w(MRB_INTEGER_DIVISION)

  conf.linker.command = 'emcc'
end

emscripten.rake

MRuby::Toolchain.new(:emscripten) do |conf|
  toolchain :clang

  conf.compilers.each do |cc|
    cc.command = "emcc"
    cc.flags.flatten!
    cc.flags.reject! { |v| v =~ /^-g/ }
  end
  conf.archiver.command = "emar"
  conf.cxx.command = "em++"

  conf.linker.command = "emcc"
  conf.linker.libraries.reject! { |v| v == 'm' }

  conf.exts do |v|
    v.executable = '.js'
    v.library = '.a'
    v.object = '.o.bc'
  end
end