> Use an IDE.

Explain.

IDEs provide graphical debuggers and colorization to show which code actually gets compiled.

For example on Visual Studio, paths not taken on conditional code get grayed out.

You disappoint me pjmlp, you're not a true graybeard unless you use Vim or Emacs :o)

The slightly more serious question: is there anything like this in Vim or Emacs-land? I somehow doubt it... I, for one, have never seen something like it outside of the big IDEs (Visual Studio, IntelliJ, etc.)

I am an ex-XEmacs user, and used vi on Xenix, DG/UX if that makes you happy. :)

Always been an IDE fan since Turbo Pascal 6.0 with its Turbo Vision based IDE.

rtags for Emacs does this, as well as completion, highlighting syntax errors, and various other IDE-like features.

Got any demo for that? I couldn't find the "highlight unused code" thing...