------- Comment #8 from matz at gcc dot gnu dot org 2010-08-16 00:55 ------- Well, okay, (3) indeed is valid ISO C (no warning) and works on POSIX 2008. I'd find it very awkward to write such work-around for (1) just so the warning in strict ISO C mode is silenced. I find this case different from other cases where such warnings about standard violations are explicitely wanted even though perhaps the code happens to work. I think it's different from those cases because POSIX (mostly concerned with portability) is a standard too, one that we'd probably like to adhere to on some systems.
Hence, I still would suggest to not warn about solution (1), even in ISO C mode. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45289
