mkmf.rbで$CFLAGS << '-Werror'をつかう
try_funcがgcc warning出すのを避けるぱっち
require 'mkmf' # replace f**king try_func def try_func(func, libs, headers = nil, &b) headers = cpp_include(headers) try_link(<<"SRC", libs, &b) or #{headers} /*top*/ #{MAIN_DOES_NOTHING} int t() { void ((*volatile p)()); p = (void ((*)()))#{func}; return 0; } SRC try_link(<<"SRC", libs, &b) #{headers} /*top*/ #{MAIN_DOES_NOTHING} int t() { extern void #{func}(void); #{func}(); return 0; } SRC end