https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85930
Bug ID: 85930 Summary: Misaligned reference created in shared_ptr_base.h with -fno-rtti Product: gcc Version: 8.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: andrey.vihrov at gmail dot com Target Milestone: --- Compiling and running the following code: #include <memory> extern const char c = 42; int main() { std::make_shared<int>(); } with "g++ -fno-rtti -fsanitize=undefined test.cpp" gives /usr/include/c++/8.1.0/bits/shared_ptr_base.h:520:54: runtime error: reference binding to misaligned address 0x5625f607b75c for type 'const struct type_info', which requires 8 byte alignment 0x5625f607b75c: note: pointer points here 72 2e 68 00 00 00 00 00 01 1b 03 3b 34 02 00 00 45 00 00 00 00 dc ff ff 80 02 00 00 a0 dc ff ff ^ This was introduced in r247905, which fixed PR 80285. g++ -v: Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/8.1.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp Thread model: posix gcc version 8.1.0 (GCC)