https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104336
Bug ID: 104336
Summary: bogus -Wrestrict for std::string assignment with
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
The following false positive was reported in
https://bugzilla.redhat.com/show_bug.cgi?id=2047428. It boils down to the same
underlying problem as in pr98465.
$ cat t.C && g++ -O2 -S -Wall -D_GLIBCXX_ASSERTIONS t.C
#include <string>
std::string s;
void f (void)
{
s = "/";
}
In file included from
/build/gcc-master/x86_64-pc-linux-gnu/libstdc++-v3/include/string:40,
from ../t.C:1:
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
/build/gcc-master/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:423:21,
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
/build/gcc-master/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:418:7,
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
/build/gcc-master/x86_64-pc-linux-gnu/libstdc++-v3/include/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
/build/gcc-master/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:1647:19,
inlined from ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::operator=(const _CharT*)
[with _CharT = char; _Traits = std::char_traits<char>; _Alloc =
std::allocator<char>]’ at
/build/gcc-master/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:815:28,
inlined from ‘void f()’ at ../t.C:7:7:
/build/gcc-master/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/char_traits.h:431:56:
warning: ‘void* __builtin_memcpy(void*, const void*, long unsigned int)’
accessing 9223372036854775810 or more bytes at offsets -4611686018427387902 and
[-4611686018427387903, 4611686018427387904] may overlap up to
9223372036854775813 bytes at offset -3 [-Wrestrict]
431 | return static_cast<char_type*>(__builtin_memcpy(__s1, __s2,
__n));
|
~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
