title: Looping over files matching wildcard in CMake
body: <p>I want to use CMake to run some tests.  One of the test should call a validator script on all files matching "fixtures/*.ext".  How can transform the following pseudo-CMake into real CMake?</p>
  
  <pre><code>i=0
  for file in fixtures/*.ext; do
    ADD_TEST(validate_${i}, "validator", $file)
    let "i=i+1"
  done
  </code></pre>