title: How To Get g++ to list paths to all #included files
body: <p>I would like to have g++/gcc tell me the paths to everything non-system it is #include-ing in C++ build.  Turns out, that is a tough search as Google mus-interprets it about ten different ways.</p>
  
  <p>I want these filenames and paths so I can add them to the search path for Exuberant CTAGS.  We have a huge project and if I use ctags on the whole thing it takes about half an hour to generate the tags file and nearly as long for the editor to do a look-up.</p>
  
  <p>We use CMakeLisats to do the compiling.  If there is a directive I can paste into the CMakeLists.txt, that would be extra wonderfulness.</p>
  
  <p>I don't really need the default paths and filenames, Johnathan Wakely gave a good tool for that <a href="https://stackoverflow.com/questions/11946294/dump-include-paths-from-g">here</a>.  I think that pretty much covers the fact that this is a cross compile job.  I don't need the cross-system files either.</p>