2014-04-11  Tobias Burnus  <burnus@net-b.de>

        PR c/60194
gcc/
        * doc/invoke.texi (-Wformat-signedness): Document it.
        (Wformat=2): Mention that this enables -Wformat-signedness.

gcc/c-family/
        * c.opt (Wformat-signedness): Add
        * c-format.c(check_format_types): Use it.

gcc/testsuite/
        * * g++.dg/warn/warn_format_signedness.C: New.
        * gcc.dg/format/warn-signedness.c: New.

From-SVN: r209328