Well, I'm about to give up, but I'll ask one last question. You see, the question you're asking doesn't make any sense. No correct C or C++ can possibly be affected by whether literal strings are in writable memory or not, so your request is utterly baffling.
Some really ancient (pre-ISO C) code requires it. Older GCC versions had a -fwritable-strings option for this. Your suggestion to fix the code is of course the right way to go :-) Segher