https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117355
--- Comment #1 from Sam James <sjames at gcc dot gnu.org> --- $ gcc-14 foo.cxx -Og -ggdb3 -o /tmp/a && /tmp/a # nothing $ gcc-15 foo.cxx -Og -ggdb3 -o /tmp/a && /tmp/a In file included from /usr/include/string.h:548, from /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/cstring:48, from foo.cxx:3: In function ‘char* strncpy(char*, const char*, size_t)’, inlined from ‘void gen_blr(const char*)’ at foo.cxx:21:22: /usr/include/bits/string_fortified.h:100:34: warning: ‘char* __builtin___strncpy_chk(char*, const char*, long unsigned int, long unsigned int)’ writing 3 bytes into a region of size 0 overflows the destination [-Wstringop-overflow=] 100 | return __builtin___strncpy_chk (__dest, __src, __len, | ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~ 101 | __glibc_objsize (__dest)); | ~~~~~~~~~~~~~~~~~~~~~~~~~ *** buffer overflow detected ***: terminated Aborted (core dumped) /tmp/a