build libbel on gem install

what is working:
- libbel builds using autools
- bel gem picks up libbel.so
- BEL::Completion api works

problems:
- make clean doesn't properly clear some build files. this is a problem
  with the Makefile.am settings in libbel.
- requires ragel for gem installation

refs OpenBEL#22

Author: Anthony Bargnesi

Rakefile

@@ -33,5 +33,7 @@ task :default => :unit
 
 require 'yard'
 YARD::Rake::YardocTask.new
+
+FileList['tasks/**/*.rake'].each { |task| import task }
 # vim: ts=2 sw=2:
 # encoding: utf-8

bel.gemspec

@@ -10,11 +10,12 @@ Gem::Specification.new do |spec|
   spec.authors            = ['Anthony Bargnesi']
   spec.date               = %q{2014-01-13}
   spec.email              = %q{[email protected]}
-  spec.files              = [
-                              Dir.glob('lib/**/*.rb'),
-                              Dir.glob('*.md'),
-                              'LICENSE'
-                            ].flatten
+  spec.files              = %w(INSTALL.md INSTALL_RUBY.md LICENSE README.md)
+  spec.files              += Dir.glob("lib/**/*.rb")
+  spec.files              += Dir.glob("ext/**/*.[ch]")
+  spec.files              += Dir.glob("vendor/libbel/{AUTHORS,ChangeLog,COPYING,INSTALL,NEWS,README}")
+  spec.files              += Dir.glob("vendor/libbel/{autogen.sh,configure.ac,Makefile.am}")
+  spec.files              += Dir.glob("vendor/libbel/{src}/*")
   spec.executables        = Dir.glob('bin/*').map(&File.method(:basename))
   spec.homepage           = 'https://github.com/OpenBEL/bel.rb'
   spec.require_paths      = ["lib"]
@@ -32,6 +33,8 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version \
                           = '>= 1.9.2'
 
+  spec.extensions         << 'ext/bel/extconf.rb'
+
   # runtime
   spec.add_dependency             'ffi',           '~> 1.9'
 

ext/bel/extconf.rb

@@ -0,0 +1,32 @@
+require 'mkmf'
+
+RbConfig::MAKEFILE_CONFIG['CC'] = ENV['CC'] if ENV['CC']
+
+$CFLAGS << " #{ENV["CFLAGS"]}"
+$CFLAGS << " -g"
+$CFLAGS << " -O3" unless $CFLAGS[/-O\d/]
+$CFLAGS << " -Wall -Wno-comment"
+
+if !(MAKE = find_executable('gmake') || find_executable('make'))
+  abort "ERROR: GNU make is required to build Rugged."
+end
+
+CWD = File.expand_path(File.dirname(__FILE__))
+LIBBEL_DIR = File.join(CWD, '..', '..', 'vendor', 'libbel')
+
+Dir.chdir(LIBBEL_DIR) do
+  system("./autogen.sh")
+  system("./configure")
+  system("#{MAKE} clean all")
+end
+
+# By putting the path to the vendored libbel library at the front of
+# $DEFLIBPATH, we can ensure that our bundled version is always used.
+$DEFLIBPATH.unshift("#{LIBBEL_DIR}/src/.libs")
+dir_config('bel', "#{LIBBEL_DIR}/src/.libs")
+
+unless have_library 'bel'
+  abort "ERROR: Failed to build libbel"
+end
+
+create_makefile("bel/bel")

tasks/ext.rake

@@ -0,0 +1,3 @@
+require 'rake/extensiontask'
+
+Rake::ExtensionTask.new('bel')