https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113674
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Note that [[____pure____]] int g (int i) { return i; } doesn't crash: pure isn't a standard attribute. The crash seems to occur only with an attribute that is registered twice: the GNU version and the standard version.