https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105545
Bug ID: 105545 Summary: Compiling string assignment with _GLIBCXX_ASSERTIONS defined fails in 12.1.0, works in 11.1.0 Product: gcc Version: 12.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: jvb at cyberscience dot com Target Milestone: --- Compiling using -D_GLIBCXX_ASSERTIONS fails in gcc 12.1.0, worked in 11.1.0: #include <string> extern std::string a(); std::string a() { std::string x; x.assign( "Z" ); return x; } using command line: g++ -m64 -c -std=gnu++17 -Wall -O3 -Werror -D_GLIBCXX_ASSERTIONS x.cpp fails with: In file included from /usr/local/gcc-12.1.0/include/c++/12.1.0/string:40, from x.cpp:14: In static member function ??static std::char_traits<char>::char_type* std::char_traits<char>::copy(char_type*, const char_type*, std::size_t)??, inlined from ??static void std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_S_copy(_CharT*, const _CharT*, size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]?? at /usr/local/gcc-12.1.0/include/c++/12.1.0/bits/basic_string.h:423:21, inlined from ??std::__cxx11::basic_string<_CharT, _Traits, _Allocator>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_M_replace(size_type, size_type, const _CharT*, size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]?? at /usr/local/gcc-12.1.0/include/c++/12.1.0/bits/basic_string.tcc:532:22, inlined from ??std::__cxx11::basic_string<_CharT, _Traits, _Alloc>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::assign(const _CharT*) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]?? at /usr/local/gcc-12.1.0/include/c++/12.1.0/bits/basic_string.h:1647:19, inlined from ??std::string a()?? at x.cpp:22:12: /usr/local/gcc-12.1.0/include/c++/12.1.0/bits/char_traits.h:431:56: error: ??void* __builtin_memcpy(void*, const void*, long unsigned int)?? accessing 9223372036854775810 or more bytes at offsets [2, 9223372036854775807] and 17 may overlap up to 9223372036854775813 bytes at offset -3 [-Werror=restrict] 431 | return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n)); | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ cc1plus: all warnings being treated as errors