Did you know about GCC's --help=CLASS syntax, like --help=warnings ? I didn't either, but your post motivated me to look it up. That's a bit like what you'd w

Did you know about GCC's --help=CLASS syntax, like --help=warnings ? I didn't either, but your post motivated me to look it up. That's a bit like what you'd want--help only for specific types of things--but it has some bizarre aspects, such as no apparent CLASS defined by operation [-c|-S|-E], so there is still no obvious way to know from the docs that the only option relevant with -E is -D (I think!). Another fun quirk is --help=undocumented, to "Display only those options which are undocumented."