title: Run Only Custom Build Rules - VS2012
body: <p>I'm upgrading one of our applications at work at I've run into a snag.  We have some "custom" languages, which are handled via a custom build rule on the file.  However, there are other projects that rely on these files being generated before they can properly build, but project with the "custom" generated files needs other projects before it can build.  The super jenky solution I have is to build the generated code projects, they fail, but generate the necessary code, then build the dependencies.</p>
  
  <p>What I want to do is run all of the custom build rules <em>before</em> actually build any project in a solution.  Is there a way to do this?</p>
  
  <p>Thanks!</p>