------- Comment #2 from manu at gcc dot gnu dot org 2007-03-07 17:57 ------- The documentation says that you should use -pedantic to warn about GCC extensions[*], so I am not sure whether this is valid. But honestly, from the description of "-std=", I would understand that GNU extensions are disabled when using -std=c89 or that pedantic does not warn for them when using -std=gnu89, but neither of those are true.
[*] http://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html#C-Extensions -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28368