title: How to collect source files with CMake without globbing?
body: <p>The <a href="http://www.cmake.org/cmake/help/v2.8.8/cmake.html#command:file" rel="noreferrer">CMake documentation</a> explicitly states that <code>file(GLOB ...)</code> is not
  recommended to collect source files for a build, but it doesn't
  mention what the recommended method actually is.</p>
  
  <p>Specifying every source file manually sounds a little bit too manually
  to me. So, what is the right method to collect source files, if not
  <code>file(GLOB ...)</code>?</p>