proposal - draft for gfortran formula

gfortran.rb

require 'formula'

class GfortranPkgDownloadStrategy <CurlDownloadStrategy
  def stage
    # The 4.2.4 compiler is distributed as a OS X 10.5
    # package- a single flat xar archive instead of a
    # bundle.
    safe_system "/usr/bin/xar -xf #{@tarball_path}"
    chdir

    # Clean up.
    safe_system "mv *.pkg/Payload Payload.gz"
    safe_system "ls | grep -v Payload | xargs rm -r"
  end
end

class GfortranDmgDownloadStrategy <CurlDownloadStrategy
  def stage
    # extract Archive.pax.gz from the PKG/DMG.
    safe_system "hdiutil attach #{@tarball_path}"
    safe_system "cp -pr /Volumes/gfortran*/gfortran.pkg/Contents/Archive.pax.gz ."
    safe_system "hdiutil detach /Volumes/gfortran*"
  end
end

class Gfortran < Formula
  if MacOS.leopard?
    url 'http://r.research.att.com/gfortran-42-5577.pkg'
    md5 '30fb495c93cf514003cdfcb7846dc701'
    version "4.2.4-5577"
  elsif MACOS_VERSION == 10.6
    # Snow Leopard
    case gcc_42_build
    when 5659
      url 'http://r.research.att.com/gfortran-42-5659.pkg'
      md5 '71bd546baa45c9c0fb4943cdd72ee274'
      version "4.2.4-5659"
    else
      # This version works for XCode 3.2.3-4.0 on Snow Leopard.
      url 'http://r.research.att.com/gfortran-42-5664.pkg'
      md5 'eb64ba9f8507da22e582814a69fbb7ca'
      version "4.2.4-5664"
    end
  else
    # Lion 64 Bit for now
    url 'http://quatramaran.ens.fr/~coudert/gfortran/gfortran-4.6.2-x86_64-Lion.dmg'
    md5 '60b59cf90d78eb601c4fd0bd1393e94d'
    version "4.6.2"
  end

  homepage 'http://r.research.att.com/tools/'

  def download_strategy
    # look at the machine environment & determine download strategy
    # options are (GfortranDmgDownloadStrategy | GfortranPkgDownloadStrategy)

    # used exception handling mechanism here, homebrew doesn't seem to allow
    # simpler $?.exitstatus checks
    begin
        safe_system "which gcc-4.2"
    rescue
        GfortranDmgDownloadStrategy
    else
        GfortranPkgDownloadStrategy
    end
  end

  # Shouldn't strip compiler binaries.
  skip_clean [ 'bin', 'lib', 'libexec' ]

  def install
    # The version of pax jumped 16 years in development between OS X 10.5
    # and OS X 10.6. In that time it became security concious. Additionally,
    # there are some slight variations in the packaging- because of this
    # installation is broken down by GCC version.
    case gcc_42_build
    when 5577
      ohai "Installing gfortran 4.2.4 for XCode 3.1.4 (build 5577)"
      safe_system "pax -rz -f Payload.gz -s ',./usr,#{prefix},'"
      # The 5577 package does not contain the gfortran->gfortran-4.2 symlink
      safe_system "ln -sf #{bin}/gfortran-4.2 #{bin}/gfortran"
      safe_system "ln -sf #{man1}/gfortran-4.2.1 #{man1}/gfortran.1"
    when 5659
      ohai "Installing gfortran 4.2.4 for XCode 3.2.2 (build 5659)"
      safe_system "pax --insecure -rz -f Payload.gz -s ',./usr,#{prefix},'"
      safe_system "ln -sf #{man1}/gfortran-4.2.1 #{man1}/gfortran.1"
    when 5664
      ohai "Installing gfortran 4.2.4 for XCode 3.2.3 (build 5664)"
      safe_system "pax --insecure -rz -f Payload.gz -s ',./usr,#{prefix},'"
      safe_system "ln -sf #{man1}/gfortran-4.2.1 #{man1}/gfortran.1"
    when 5666
      ohai "Installing gfortran 4.2.4 for XCode 3.2.6--4.1 (build 5666)"
      safe_system "pax --insecure -rz -f Payload.gz -s ',./usr,#{prefix},'"
      safe_system "ln -sf #{man1}/gfortran-4.2.1 #{man1}/gfortran.1"
    else
      ohai "Installing gfortran 4.6.2 ..."
      safe_system "pax --insecure -rz -f Archive.pax.gz -s ',.#{HOMEBREW_PREFIX}/gfortran,#{prefix},'"

      # remove files from cellar that we don't want to symlink
      # older libs to suppress link warnings (not needed under 10.7 anyway)
      safe_system "rm #{prefix}/lib/libgcc_ext.10.4.dylib;rm #{prefix}/lib/libgcc_ext.10.5.dylib"
      
      # avoid anything outside of gfortran that could mess w/ other user needs
      safe_system "rm #{prefix}/bin/cpp;rm #{prefix}/bin/g++;rm #{prefix}/bin/gcc;rm #{prefix}/bin/gcov"
    end
  end

  def caveats; <<-EOS.undent
    Brews that require a Fortran compiler should not use:
      depends_on 'gfortran'

    The preferred method of declaring Fortran support is to use:
      def install
        ...
        ENV.fortran
        ...
      end

      EOS
  end
end