Allow formulae to use __END__

For this to work the "running script" must be the formulae file. Making this
so wasn't so hard, there is now an install.rb script which is included with
the -r flag to the ruby executable. An at_exit handler calls the install
function.

Having the install logic in its own file made it feel like there was so much
space that I added extra error handling. So there is something to be said for
separating functionality out into its own files.

Still the error handling sucks, we'll need to marshall the exception back to
the bin/brew command. Which is another PITA.

Still overall I think this will prove worthwhile. But if it doesn't we'll
revert.

As a first usage, you can put a diff after __END__ and return DATA from
Formula::patches to make Homebrew aware of it.

1 files changed, 78 insertions, 0 deletions

diff --git a/Library/Homebrew/install.rb b/Library/Homebrew/install.rb
new file mode 100755
index 000000000..72fb2a1fa
--- /dev/null
+++ b/Library/Homebrew/install.rb
@@ -0,0 +1,78 @@
+#!/usr/bin/ruby
+require 'global'
+require 'formula'
+require 'keg'
+require 'brew.h'
+
+def install f  
+  build_time=nil
+
+  begin
+    f.brew do
+      if ARGV.flag? '--interactive'
+        ohai "Entering interactive mode"
+        puts "Type `exit' to return and finalize the installation"
+        puts "Install to this prefix: #{f.prefix}"
+        interactive_shell
+        nil
+      elsif ARGV.include? '--help'
+        system './configure --help'
+        exit $?
+      else
+        f.prefix.mkpath
+        beginning=Time.now
+        f.install
+        %w[README ChangeLog COPYING LICENSE COPYRIGHT AUTHORS].each do |file|
+          FileUtils.mv "#{file}.txt", file rescue nil
+          f.prefix.install file rescue nil
+        end
+        build_time=Time.now-beginning
+      end
+    end
+  rescue Exception
+    if f.prefix.directory?
+      f.prefix.rmtree
+      f.prefix.parent.rmdir_if_possible
+    end
+    raise
+  end
+
+  ohai "Caveats", f.caveats, ''
+  ohai 'Finishing up' if ARGV.verbose?
+  
+  begin
+    clean f
+  rescue Exception => e
+    opoo "The cleaning step did not complete successfully"
+    puts "Still, the installation was successful, so we will link it into your prefix"
+    ohai e, e.inspect if ARGV.debug?
+  end
+
+  raise "Nothing was installed to #{f.prefix}" unless f.installed?
+
+  begin
+    Keg.new(f.prefix).link
+  rescue Exception
+    onoe "The linking step did not complete successfully"
+    puts "The package built, but is not symlinked into #{HOMEBREW_PREFIX}"
+    puts "You can try again using `brew link #{f.name}'"
+    ohai e, e.inspect if ARGV.debug?
+    ohai "Summary"
+  else
+    ohai "Summary" if ARGV.verbose?
+  end
+
+  print "#{f.prefix}: #{f.prefix.abv}"
+  print ", built in #{pretty_duration build_time}" if build_time
+  puts
+
+rescue Exception => e
+  #TODO propogate exception back to brew script
+  onoe e
+  puts e.backtrace
+end
+
+
+# I like this little at all, but see no alternative seeing as the formula
+# rb file has to be the running script to allow it to use __END__ and DATA
+at_exit { install(Formula.factory($0)) }