From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 5BEE03858D3C; Wed, 11 Jan 2023 00:23:57 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5BEE03858D3C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1673396637; bh=xbw06pcT7Iv0YJ7HHnvqLEZ+KJM1xB7Mx40Gl+2JkBQ=; h=From:To:Subject:Date:In-Reply-To:References:From; b=bemmzOiLD1wTzxCUCNMsbvtsRhi8ddIpOS6y2NhhcbTNZxZTFxxCt+1oY5kER2cRc AwFVsWBNrMSpAYz/46K+eK8+KofHQUZfXmaH5UQZ2IkNnIklCLXg597D7gmjnkGLLn udKoJyiFL+JOt7SeEBpy4KX/QDbJfmy+fnzO/3VI= From: "BenWiederhake.GitHub at gmx dot de" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/108366] [12/13 Regression] Spurious stringop overflow, possibly alias-related Date: Wed, 11 Jan 2023 00:23:56 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Version: 12.2.0 X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: BenWiederhake.GitHub at gmx dot de X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 12.3 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108366 --- Comment #1 from Ben Wiederhake --- Preprocessed file see attachments, and output as generated by -v -save-temps here: $ g++ -v -o foo -O2 -std=3Dc++20 -save-temps repro.cpp=20 Using built-in specs. COLLECT_GCC=3Dg++ COLLECT_LTO_WRAPPER=3D/usr/lib/gcc/x86_64-linux-gnu/12/lto-wrapper OFFLOAD_TARGET_NAMES=3Dnvptx-none:amdgcn-amdhsa OFFLOAD_TARGET_DEFAULT=3D1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion=3D'Debian 12.2.0-13' --with-bugurl=3Dfile:///usr/share/doc/gcc-12/README.Bugs --enable-languages=3Dc,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=3D/usr --with-gcc-major-version-only --program-suffix=3D-12 --program-prefix=3Dx86_64-linux-gnu- --enable-shared --enable-linker-build-= id --libexecdir=3D/usr/lib --without-included-gettext --enable-threads=3Dposix --libdir=3D/usr/lib --enable-nls --enable-clocale=3Dgnu --enable-libstdcxx-= debug --enable-libstdcxx-time=3Dyes --with-default-libstdcxx-abi=3Dnew --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=3Drelea= se --with-target-system-zlib=3Dauto --enable-objc-gc=3Dauto --enable-multiarch --disable-werror --enable-cet --with-arch-32=3Di686 --with-abi=3Dm64 --with-multilib-list=3Dm32,m64,mx32 --enable-multilib --with-tune=3Dgeneric --enable-offload-targets=3Dnvptx-none=3D/build/gcc-12-PBog5r/gcc-12-12.2.0/= debian/tmp-nvptx/usr,amdgcn-amdhsa=3D/build/gcc-12-PBog5r/gcc-12-12.2.0/deb= ian/tmp-gcn/usr --enable-offload-defaulted --without-cuda-driver --enable-checking=3Drelease --build=3Dx86_64-linux-gnu --host=3Dx86_64-linux-gnu --target=3Dx86_64-linu= x-gnu Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 12.2.0 (Debian 12.2.0-13)=20 COLLECT_GCC_OPTIONS=3D'-v' '-o' 'foo' '-O2' '-std=3Dc++20' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-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=3Dgeneric -march=3Dx86-64 -std=3Dc++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-fi= xed" 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=3D'-v' '-o' 'foo' '-O2' '-std=3Dc++20' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-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=3Dgeneric -march=3Dx86-64 -O2 -std=3Dc++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=3D100 --param ggc-min-heapsize=3D131= 072 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=3D100 --param ggc-min-heapsize=3D131= 072 Compiler executable checksum: b9e5387ca128f541a98a8ca5afd00294 In function =E2=80=98Vector make_vector()=E2=80=99, inlined from =E2=80=98int main()=E2=80=99 at repro.cpp:36:31: repro.cpp:27:11: warning: =E2=80=98void* memset(void*, int, size_t)=E2=80= =99 writing 128 bytes into a region of size 40 overflows the destination [-Wstringop-overflow=3D] 27 | memset(buffer.data(), 'A', new_size); | ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ repro.cpp: In function =E2=80=98int main()=E2=80=99: repro.cpp:36:10: note: destination object =E2=80=98actual=E2=80=99 of size = 40 36 | auto actual =3D make_vector(); | ^~~~~~ COLLECT_GCC_OPTIONS=3D'-v' '-o' 'foo' '-O2' '-std=3Dc++20' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-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=3D/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=3D/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/:/us= r/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/12/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS=3D'-v' '-o' 'foo' '-O2' '-std=3Dc++20' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-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=3D/usr/lib/gcc/x86_64-linux-gnu/12/lto-wrapper -plugin-opt=3D-fresolution=3Dfoo.res -plugin-opt=3D-pass-through=3D-lgcc_s -plugin-opt=3D-pass-through=3D-lgcc -plugin-opt=3D-pass-through=3D-lc -plugin-opt=3D-pass-through=3D-lgcc_s -plugin-opt=3D-pass-through=3D-lgcc -= -build-id --eh-frame-hdr -m elf_x86_64 --hash-style=3Dgnu --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-gn= u/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=3D'-v' '-o' 'foo' '-O2' '-std=3Dc++20' '-save-temps' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' '-dumpdir' 'foo.'=