http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52347
--- Comment #4 from Simon Richter <Simon.Richter at hogyros dot de> --- Testcase is simple: $ cat tt.cpp void bar(int baz) { } $ g++-4.7 -c -W -Wall -Werror -Wno-unused tt.cpp $ g++-4.8 -c -W -Wall -Werror -Wno-unused tt.cpp tt.cpp:1:6: error: unused parameter ‘baz’ [-Werror=unused-parameter] void bar(int baz) { } ^ cc1plus: all warnings being treated as errors