title: Setting compiler specific flags in scons
body: <p>When writing a scons script that will be used on different platform and compiler it's sometimes desired to add compiler specific flags. Fx in pseudo code</p>
  
  <pre><code>if using_gcc:
      env.Append( CCFLAGS=["-g"] )
  elif using_msvc:
      env.Append( CCFLAGS=["/Zi"] )
  </code></pre>
  
  <p>At an earlier occation I just copied the appropriate(?) <code>.py</code> files under <code>Tools</code> and modified these and placed under <code>site_tools</code>, but that seems like a hackish solution.</p>
  
  <p>Is there a better way to achieve this result? It would of course be nice if it could be added under <code>site_scons</code> to take global effect (without having to resort to hacking the tools files themselves).</p>
  
  <p>Note: The reason I find it desirable to do this under <code>site_scons</code> is that it could be done a part of a common build system that is shared among multiple projects. Naturally this means that one have to share this build system among all participants in the project too.</p>