title: extra_compile_args in Cython
body: <p>I want to pass some extra options to the <code>Cython</code> compiler by using <code>extra_compile_args</code>.</p>
  
  <p>My <code>setup.py</code>:</p>
  
  <pre><code>from distutils.core import setup
  
  from Cython.Build import cythonize
  
  setup(
    name = 'Test app',
    ext_modules = cythonize("test.pyx", language="c++", extra_compile_args=["-O3"]),
  )
  </code></pre>
  
  <p>However, when I run <code>python setup.py build_ext --inplace</code>, I get the following warning:</p>
  
  <pre><code>UserWarning: got unknown compilation option, please remove: extra_compile_args
  </code></pre>
  
  <p><strong>Question:</strong> How does one use <code>extra_compile_args</code> correctly?</p>
  
  <p>I use <code>Cython 0.23.4</code> under <code>Ubuntu 14.04.3</code>.</p>