https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108366
--- Comment #1 from Ben Wiederhake <BenWiederhake.GitHub at gmx dot de> --- Preprocessed file see attachments, and output as generated by -v -save-temps here: $ g++ -v -o foo -O2 -std=c++20 -save-temps repro.cpp Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/12/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Debian 12.2.0-13' --with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-12 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-12-PBog5r/gcc-12-12.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-12-PBog5r/gcc-12-12.2.0/debian/tmp-gcn/usr --enable-offload-defaulted --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 12.2.0 (Debian 12.2.0-13) COLLECT_GCC_OPTIONS='-v' '-o' 'foo' '-O2' '-std=c++20' '-save-temps' '-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' 'foo-' /usr/lib/gcc/x86_64-linux-gnu/12/cc1plus -E -quiet -v -imultiarch x86_64-linux-gnu -D_GNU_SOURCE repro.cpp -mtune=generic -march=x86-64 -std=c++20 -O2 -fpch-preprocess -fasynchronous-unwind-tables -o foo-repro.ii ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/12" ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/12/include-fixed" ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/12/../../../../x86_64-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /usr/include/c++/12 /usr/include/x86_64-linux-gnu/c++/12 /usr/include/c++/12/backward /usr/lib/gcc/x86_64-linux-gnu/12/include /usr/local/include /usr/include/x86_64-linux-gnu /usr/include End of search list. COLLECT_GCC_OPTIONS='-v' '-o' 'foo' '-O2' '-std=c++20' '-save-temps' '-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' 'foo-' /usr/lib/gcc/x86_64-linux-gnu/12/cc1plus -fpreprocessed foo-repro.ii -quiet -dumpdir foo- -dumpbase repro.cpp -dumpbase-ext .cpp -mtune=generic -march=x86-64 -O2 -std=c++20 -version -fasynchronous-unwind-tables -o foo-repro.s GNU C++20 (Debian 12.2.0-13) version 12.2.0 (x86_64-linux-gnu) compiled by GNU C version 12.2.0, GMP version 6.2.1, MPFR version 4.1.1-p1, MPC version 1.3.1, isl version isl-0.25-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C++20 (Debian 12.2.0-13) version 12.2.0 (x86_64-linux-gnu) compiled by GNU C version 12.2.0, GMP version 6.2.1, MPFR version 4.1.1-p1, MPC version 1.3.1, isl version isl-0.25-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: b9e5387ca128f541a98a8ca5afd00294 In function ‘Vector make_vector()’, inlined from ‘int main()’ at repro.cpp:36:31: repro.cpp:27:11: warning: ‘void* memset(void*, int, size_t)’ writing 128 bytes into a region of size 40 overflows the destination [-Wstringop-overflow=] 27 | memset(buffer.data(), 'A', new_size); | ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ repro.cpp: In function ‘int main()’: repro.cpp:36:10: note: destination object ‘actual’ of size 40 36 | auto actual = make_vector(); | ^~~~~~ COLLECT_GCC_OPTIONS='-v' '-o' 'foo' '-O2' '-std=c++20' '-save-temps' '-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' 'foo-' as -v --64 -o foo-repro.o foo-repro.s GNU assembler version 2.39.90 (x86_64-linux-gnu) using BFD version (GNU Binutils for Debian) 2.39.90.20230104 COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/12/:/usr/lib/gcc/x86_64-linux-gnu/12/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/12/:/usr/lib/gcc/x86_64-linux-gnu/ LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/12/:/usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/12/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/12/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-o' 'foo' '-O2' '-std=c++20' '-save-temps' '-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' 'foo.' /usr/lib/gcc/x86_64-linux-gnu/12/collect2 -plugin /usr/lib/gcc/x86_64-linux-gnu/12/liblto_plugin.so -plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/12/lto-wrapper -plugin-opt=-fresolution=foo.res -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie -o foo /usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu/Scrt1.o /usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/12/crtbeginS.o -L/usr/lib/gcc/x86_64-linux-gnu/12 -L/usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/12/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/12/../../.. foo-repro.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/12/crtendS.o /usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu/crtn.o COLLECT_GCC_OPTIONS='-v' '-o' 'foo' '-O2' '-std=c++20' '-save-temps' '-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' 'foo.'