title: How do I use bazel to produce multiple files from the same set of input files
body: <p>I have a simple project which uses <a href="http://www.swig.org/" rel="nofollow noreferrer">SWIG</a> to make a small C++ library available to C#. The C++ part is a single source and a single header file -- in addition there is one SWIG interface file. The output from SWIG consists of 5 C# source files and 1 C++ source file.</p>
  
  <p>Doing this with <code>make</code> is fairly simple, but I'm having a few problems wrapping my head around bazel.</p>
  
  <p>How can I tell bazel that those 6 files are <em>all</em> generated using the same command? Also, while I'm at it, how I do I tell bazel to actually invoke that command.</p>
  
  <p>The end product, that I'm ultimately interested in, is a .net dll file which only depend on the interface file and the original C++ header file.</p>