Seeing how long the thread on gcc-patches on what comments -Wimplicit-fallthrough should recognize has gotten, I thought it might be a good idea to start a discussion on lint-style comments more generally. Instead of just limiting the use of lint-style comments to -Wimplicit-fallthrough, why not split the recognition of it off into a separate switch (-flint-style-comments or -Wlint-style-comments) that can be taken advantage of by other warnings? Here are some examples I've seen in actual code: /*NOTREACHED*/ to tell the compiler that code is unreachable; could be useful if the -Wunreachable-code warning were to be revived. I suggested making this equivalent to __builtin_unreachable() on a bug on bugzilla, but apparently that also affects codegen, so instead of making the two exactly equivalent, how about if the comment just silences the warning and leaves the codegen the same? /*ARGSUSED*/ which is pretty similar to __attribute__((unused)) or #pragma unused; could also be used to silence -Wunused-parameter /*VARARGS*/ for functions with a variable number of arguments; I'm not aware of any GCC warnings that this one would currently silence.
Further links I found by Googling: http://csweb.cs.wfu.edu/~torgerse/Kokua/More_SGI/007-0701-150/sgi_html/apb.html (lists some other ones I hadn't seen) http://www.splint.org/manual/manual.html#annotations (scroll down to the "Traditional Lint Comments" section) https://docs.freebsd.org/info/cpp/cpp.info.Invocation.html (The FreeBSD cpp seems to have a '-lint' flag; apparently their GCC supports a #pragma lint) http://www.fnal.gov/docs/products/gcc/v2_95_2/cpp.info,.Invocation.html (seems to be the same as the previous, but with some further commentary about option naming) Anyways, what do people think?
