https://gcc.gnu.org/g:160159b272f9880dfdb5e4e8fad4bbe475567809
commit r17-983-g160159b272f9880dfdb5e4e8fad4bbe475567809 Author: Marc Poulhiès <[email protected]> Date: Thu May 28 22:11:52 2026 +0200 gccrs: workaround -Wrestrict false positive [PR114385] Recent change gives: In file included from /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/string:45, from ../../gcc/rust/rust-system.h:34, from ../../gcc/rust/lex/rust-token.cc:19: In static member function 'static constexpr std::char_traits<char>::char_type* std::char_traits<char>::copy(char_type*, const char_type*, std::size_t)', inlined from 'static constexpr 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 /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:4 87:21, inlined from 'static constexpr 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 /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:4 82:7, inlined from 'constexpr void std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_M_mutate(size_type, size_type, const _CharT*, size_type) [with _CharT = char; _Trait s = std::char_traits<char>; _Alloc = std::allocator<char>]' at /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_st ring.tcc:403:15, inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Alloc>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_M_append(const _CharT*, size_type) [ with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc+ +-v3/include/bits/basic_string.tcc:498:17, inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Alloc>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::append(const _CharT*, size_type) [wit h _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc++-v 3/include/bits/basic_string.h:1624:18, inlined from 'constexpr _Str std::__str_concat(const typename _Str::value_type*, typename _Str::size_type, const typename _Str::value_type*, typename _Str::size_type, const typename _Str::allocator_type&) [with _Str = __cxx11::basic_string<char>]' at /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc++-v3/ include/bits/basic_string.h:3908:19, inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*) [with _CharT = char; _Traits = char_traits<char>; _Alloc = allocator<char>]' at /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bi ts/basic_string.h:3984:31, inlined from 'std::string Rust::Token::as_string() const' at ../../gcc/rust/lex/rust-token.cc:251:45: /gccrs/build/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/char_traits.h:432:56: error: 'void* __builtin_memcpy(void*, const void* , long unsigned int)' accessing 18446744073709551609 or more bytes at offsets 0 and 0 overlaps 9223372036854775795 bytes at offset -9223372036854775802 [-Werror=restrict] 432 | return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n)); | ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ Split the concatenation to avoid the warning. Fix comes from https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125404#c2 gcc/rust/ChangeLog: PR tree-optimization/114385 * lex/rust-token.cc (Token::as_string): split concatenation. Co-authored-by: Andreas Schwab <[email protected]> Signed-off-by: Marc Poulhiès <[email protected]> Diff: --- gcc/rust/lex/rust-token.cc | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/gcc/rust/lex/rust-token.cc b/gcc/rust/lex/rust-token.cc index a19bed5bc5b2..41861d1b2197 100644 --- a/gcc/rust/lex/rust-token.cc +++ b/gcc/rust/lex/rust-token.cc @@ -248,12 +248,31 @@ Token::as_string () const if (get_type_hint () == CORETYPE_UNKNOWN) return get_str (); else - return get_str () + get_type_hint_str (); + /* FIXME: This is a workaround for an overzealous -Wrestrict, + #125404 - we should remove it once it is fixed + + return get_str () + get_type_hint_str (); + */ + { + std::string s = get_str (); + s += get_type_hint_str (); + return s; + } case FLOAT_LITERAL: if (get_type_hint () == CORETYPE_UNKNOWN) return get_str (); else - return get_str () + get_type_hint_str (); + /* FIXME: This is a workaround for an overzealous -Wrestrict, + #125404 - we should remove it once it is fixed + + return get_str () + get_type_hint_str (); + */ + { + std::string s = get_str (); + s += get_type_hint_str (); + return s; + } + default: return get_str (); }
