From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id C7E2F385800C; Fri, 19 Nov 2021 15:52:46 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C7E2F385800C From: "redi at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/103332] New: Spurious -Wstringop-overflow warnings in libstdc++ tests Date: Fri, 19 Nov 2021 15:52:46 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Version: 12.0 X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: redi at gcc dot gnu.org 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 keywords bug_severity priority component assigned_to reporter blocked target_milestone 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 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Nov 2021 15:52:46 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103332 Bug ID: 103332 Summary: Spurious -Wstringop-overflow warnings in libstdc++ tests Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords: diagnostic Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: redi at gcc dot gnu.org Blocks: 88443 Target Milestone: --- In the $objdir/$target/libstdc++-v3/testsuite dir, running: make check RUNTESTFLAGS=3D"conformance.exp=3D21_strings/basic_string/operators/char/1.= cc --target_board=3Dunix/-D_GLIBCXX_DEBUG" Results in: In file included from /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/stri= ng:40,^M from /home/jwakely/src/gcc/libstdc++-v3/testsuite/21_strings/basic_string/operat= ors/char/1.cc:22:^M In static member function 'static std::char_traits::char_type* std::char_traits::copy(std::char_traits::char_type*, const std::char_traits::char_type*, std::size_t)',^M inlined from 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&) [with _CharT =3D char; _Traits =3D std::char_traits; _Alloc =3D std::allocator]' at /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /basic_string.h:675,^M inlined from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, c= onst _CharT*) [with _CharT =3D char; _Traits =3D std::char_traits; _Alloc = =3D std::allocator]' at /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /basic_string.h:3552,^M inlined from 'int test01()' at /home/jwakely/src/gcc/libstdc++-v3/testsuite/21_strings/basic_string/operat= ors/char/1.cc:34:^M /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /char_traits.h:423: warning: 'void* __builtin_memcpy(void*, const void*, long unsigned int)' writing 17 bytes into a region of size 16 overflows the destination [-Wstringop-overflow=3D]^M /home/jwakely/src/gcc/libstdc++-v3/testsuite/21_strings/basic_string/operat= ors/char/1.cc: In function 'int test01()':^M /home/jwakely/src/gcc/libstdc++-v3/testsuite/21_strings/basic_string/operat= ors/char/1.cc:34: note: at offset 16 into destination object '' of size 32^M FAIL: 21_strings/basic_string/operators/char/1.cc (test for excess errors) Excess errors: /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /char_traits.h:423: warning: 'void* __builtin_memcpy(void*, const void*, long unsigned int)' writing 17 bytes into a region of size 16 overflows the destination [-Wstringop-overflow=3D] And: make check RUNTESTFLAGS=3D"conformance.exp=3D21_strings/basic_string/capacity/char/1.cc --target_board=3Dunix/-std=3Dgnu++20" results in: In file included from /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/stri= ng:40,^M from /home/jwakely/src/gcc/libstdc++-v3/testsuite/21_strings/basic_string/capaci= ty/char/1.cc:22:^M In static member function 'static constexpr std::char_traits::char_ty= pe* std::char_traits::copy(std::char_traits::char_type*, const std::char_traits::char_type*, std::size_t)',^M inlined from 'static constexpr void std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_S_copy(_CharT*, const _CharT*, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type) [with _Char= T =3D char; _Traits =3D std::char_traits; _Alloc =3D std::allocator]'= at /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /basic_string.h:423,^M inlined from 'static constexpr void std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_S_copy(_CharT*, const _CharT*, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type) [with _Char= T =3D char; _Traits =3D std::char_traits; _Alloc =3D std::allocator]'= at /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /basic_string.h:418,^M inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_M_append(const _CharT*, std::__cxx11::basic_string<_CharT, _Trait= s, _Alloc>::size_type) [with _CharT =3D char; _Traits =3D std::char_traits; _Alloc =3D std::allocator]' at /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /basic_string.tcc:417,^M inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Alloc>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::append(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&) [with _CharT =3D char; _Traits =3D std::char_traits; _Alloc =3D std::allocator]' at /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /basic_string.h:1385,^M inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>= &) [with _CharT =3D char; _Traits =3D std::char_traits; _Alloc =3D std::allocator]' at /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /basic_string.h:3433,^M inlined from 'void test01()' at /home/jwakely/src/gcc/libstdc++-v3/testsuite/21_strings/basic_string/capaci= ty/char/1.cc:102:^M /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /char_traits.h:423: warning: 'void* __builtin_memcpy(void*, const void*, long unsigned int)' specified bound between 18446744073709551586 and 18446744073709551615 excee= ds maximum object size 9223372036854775807 [-Wstringop-overflow=3D]^M FAIL: 21_strings/basic_string/capacity/char/1.cc (test for excess errors) Excess errors: /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /char_traits.h:423: warning: 'void* __builtin_memcpy(void*, const void*, long unsigned int)' specified bound between 18446744073709551586 and 18446744073709551615 excee= ds maximum object size 9223372036854775807 [-Wstringop-overflow=3D] And: make check=20 RUNTESTFLAGS"=3Dconformance.exp=3Dexperimental/filesystem/path/factory/u8pa= th-char8_t.cc --target_board=3Dunix/-std=3Dgnu++20" results in: [...] FAIL: experimental/filesystem/path/factory/u8path-char8_t.cc (test for exce= ss errors) Excess errors: /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /char_traits.h:423: warning: 'void* __builtin_memcpy(void*, const void*, long unsigned int)' reading between 16 and 9223372036854775806 bytes from a region of size 10 [-Wstringop-overread] /home/jwakely/build/powerpc64le-unknown-linux-gnu/libstdc++-v3/include/bits= /char_traits.h:423: warning: 'void* __builtin_memcpy(void*, const void*, long unsigned int)' reading between 16 and 9223372036854775806 bytes from a region of size 10 [-Wstringop-overread] These are all bogus, as far as I can tell. e.g. for the last one, we read 9 bytes from a string literal that is 10 bytes long (including the null) and memcpy it into a buffer that is 16 bytes in size. That doesn't overflow. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D88443 [Bug 88443] [meta-bug] bogus/missing -Wstringop-overflow warnings=