https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100124
--- Comment #6 from Behdad Esfahbod <gcc at behdad dot org> --- Thank you all. I understand it's unlikely to happen at this point. In reply to Andrew Pinski from comment #1) > I will let someone comment on the flexible array extension. > > But I will note GCC treats (all) arrays at the end of a POD struct as a > flexible one so the question I have is more about the ubsan issue you are > running into, is that with GCC or with clang/LLVM? The ubsan issue reported to us is with gcc: https://github.com/harfbuzz/harfbuzz/issues/2953#issuecomment-823460893