http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46803
--- Comment #7 from Jonathan Gray <jsg at openbsd dot org> 2010-12-05 12:44:55 UTC --- I don't understand the quoting suggestion, why does gcc/unwind-generic.h for example then contain lines such as typedef unsigned _Unwind_Word __attribute__((__mode__(__unwind_word__))); and perl PERL_EXPORT_C int PerlIO_printf(PerlIO *, const char *, ...) __attribute__format__(__printf__, 2, 3); Is there anything more authoritive than http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html on this?