https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64922
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> --- So, with the patch you've posted I get: $ /usr/src/gcc/obj/gcc/g++ -B /usr/src/gcc/obj/gcc/ `/usr/src/gcc/obj/x86_*/libstdc++-v3/scripts/testsuite_flags --build-includes` -E -o x.ii x.cc -O2 -D_GLIBCXX_USE_CXX11_ABI=0 $ /usr/src/gcc/obj/gcc/cc1plus -fsanitize=alignment,bool,enum,unreachable -O2 x.ii -quiet $ gcc -o x x.s /usr/src/gcc/obj/x86_64-unknown-linux-gnu/libsanitizer/ubsan/.libs/libubsan.a -lpthread -ldl /usr/src/gcc/obj/x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs/libstdc++.so -Wl,-rpath,/usr/src/gcc/obj/x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs/ $ ./pol6 a x.cc:39:3: runtime error: execution reached a __builtin_unreachable() call And the unreachable calls in there are IMHO wrong.
