From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 6C8D8385842C; Mon, 27 Mar 2023 19:04:38 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6C8D8385842C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1679943878; bh=9ns3yx7kP24IMKXRsbxHirl7zti+wOf0WBed+LrqP9I=; h=From:To:Subject:Date:From; b=Hh/bKPRF7BB9uOzVsPVeDeiyUxt9h9hCoqZrn+vWVXxc5rVR8OhM4WA5U8fV4dLM8 R640i24O9pFmNLA3PWCq9GIJzT6BDA5Uv246nijhZ429Hnshinv2hvDbYo43uwyoiH NiAeItcyRnYFAT7Wk6SxK3+T+m1ubThlOvvHDqiI= From: "marc-andre.laverdiere at synopsys dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/109305] New: Allocator copy in basic_string::operator= Date: Mon, 27 Mar 2023 19:04:37 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Version: 12.1.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: marc-andre.laverdiere at synopsys dot com 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: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone attachments.created Message-ID: 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=3D109305 Bug ID: 109305 Summary: Allocator copy in basic_string::operator=3D Product: gcc Version: 12.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: marc-andre.laverdiere at synopsys dot com Target Milestone: --- Created attachment 54773 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D54773&action=3Dedit Self-contained preprocessed reproducer In basic_string& operator=3D(const basic_string& __str), I noticed this lin= e: auto __alloc =3D __str._M_get_allocator(); This creates a local copy of the allocator object. I doubt this is intentio= nal, but I could be wrong. GCC version: 12.1.0 with the patch for 105562 Output of g++ -E -v -save-temps -c Using built-in specs. COLLECT_GCC=3Dg++ OFFLOAD_TARGET_NAMES=3Dnvptx-none:hsa OFFLOAD_TARGET_DEFAULT=3D1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion=3D'Ubuntu 9.4.0-1ubuntu1~20.04.1' --with-bugurl=3Dfile:///usr/share/doc/gcc-9/README.= Bugs --enable-languages=3Dc,ada,c++,go,brig,d,fortran,objc,obj-c++,gm2 --prefix= =3D/usr --with-gcc-major-version-only --program-suffix=3D-9 --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 --with-target-system-zlib=3Dauto --enable-objc-gc=3Dauto --enable-multiarch --disable-werror --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-9-Av3uEd/gcc-9-9.4.0/deb= ian/tmp-nvptx/usr,hsa --without-cuda-driver --enable-checking=3Drelease --build=3Dx86_64-linux-gnu --host=3Dx86_64-linux-gnu --target=3Dx86_64-linux-gnu Thread model: posix gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.1) COLLECT_GCC_OPTIONS=3D'-E' '-v' '-save-temps' '-c' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' /usr/lib/gcc/x86_64-linux-gnu/9/cc1plus -E -quiet -v -imultiarch x86_64-linux-gnu -D_GNU_SOURCE reproducer.cpp -mtune=3Dgeneric -march=3Dx86= -64 -fpch-preprocess -fasynchronous-unwind-tables -fstack-protector-strong -Wfo= rmat -Wformat-security -fstack-clash-protection -fcf-protection ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/9" ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/9/include-fix= ed" ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/9/../../../../x86_64-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /usr/include/c++/9 /usr/include/x86_64-linux-gnu/c++/9 /usr/include/c++/9/backward /usr/lib/gcc/x86_64-linux-gnu/9/include /usr/local/include /usr/include/x86_64-linux-gnu /usr/include End of search list. COMPILER_PATH=3D/usr/lib/gcc/x86_64-linux-gnu/9/:/usr/lib/gcc/x86_64-linux-= gnu/9/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/9/:/usr= /lib/gcc/x86_64-linux-gnu/ LIBRARY_PATH=3D/usr/lib/gcc/x86_64-linux-gnu/9/:/usr/lib/gcc/x86_64-linux-g= nu/9/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/9/../../../..= /lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/l= ib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/9/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS=3D'-E' '-v' '-save-temps' '-c' '-shared-libgcc' '-mtune=3Dgeneric' '-march=3Dx86-64' I'm attaching a self-contained reproducer. The statement of interest is at = line 14824.=