https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77650
--- Comment #5 from Martin Sebor <msebor at gcc dot gnu.org> --- Documenting the semantics of this extension would work, though to be usable safely, GCC would also need to change to recognize that the nested flexible array member aliases the subsequent members and treat the two sets as if they were declared in a union. My own preference, however, would be to reject such constructs in user code. As long as changing Glibc to use a zero-length array is feasible (those would continue to be accepted in this context), it should be possible to do.
