https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78635
Martin Sebor <msebor at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |msebor at gcc dot gnu.org --- Comment #11 from Martin Sebor <msebor at gcc dot gnu.org> --- This is not a dupe of bug 68489. The latter is about GCC not issuing a diagnostic for arrays of a struct with a flexible array member. The global array in the following test case (copied from that bug) is silently accepted by GCC (due to bug 71290 GCC 6 doesn't even issue the -Wpedantic warning): struct A { int n; int a []; }; struct A a[2]; y.C:3:12: warning: ISO C++ forbids zero-size array ‘a’ [-Wpedantic] int a []; ^ This bug is about an ICE for more involved definitions of arrays of structs with flexible array members. The ICE is new in GCC 6, and a separate problem from the absence of diagnostic. It may be that rejecting this code will also avoid the ICE, but I think it's best to track those problems separately. Otherwise it's easy to open a new bug for the ICE even after reviewing bug 68489 (as I myself just did in bug 80135).