Move extension to a subdirectory

.gitignore

@@ -7,6 +7,7 @@
 /site/
 /spec/reports/
 /tmp/
-ext/Makefile
-ext/*.o
-ext/*.bundle
+ext/**/Makefile
+ext/**/*.o
+ext/**/*.bundle
+*.gem

Rakefile

@@ -1,12 +1,18 @@
 require 'bundler/gem_tasks'
+require 'English'
+require 'open3'
 require 'rake/testtask'
 require 'rubocop/rake_task'
 
 task :compile do
   puts 'Compiling C extension'
-  `cd ext && make clean`
-  `cd ext && ruby extconf.rb`
-  `cd ext && make`
+  # ignore clean failure because the Makefile may not exist yet
+  cmd = 'cd ext/wordexp_ext && (make clean || true) && ruby extconf.rb && make'
+  out, status = Open3.capture2e(cmd)
+  unless status.success?
+    warn out
+    raise 'Failed to compile native extension'
+  end
   puts 'Done'
 end
 

ext/extconf.rb

@@ -1,3 +0,0 @@
-require 'mkmf'
-
-create_makefile 'wordexp_ext'

ext/wordexp_ext/extconf.rb

@@ -0,0 +1,3 @@
+require 'mkmf'
+
+create_makefile 'wordexp_ext/wordexp_ext'

ext/wordexp_ext/wordexp_ext.c

@@ -11,12 +11,10 @@
  *
  */
 
+#include <ruby.h>
 #include <string.h>
 #include <wordexp.h>
 
-#include "ruby.h"
-#include "ruby/encoding.h"
-
 static VALUE ext_wordexp(VALUE self, VALUE rstring) {
     Check_Type(rstring, T_STRING);
     char *string = RSTRING_PTR(rstring);

lib/wordexp.rb

@@ -1,4 +1,4 @@
-require 'wordexp_ext'
+require 'wordexp_ext/wordexp_ext'
 
 module Wordexp
   autoload :CLI, 'wordexp/cli'